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Contents Section: Exhaust All sections

Engine Exhaust System Chevrolet Malibu VI рестайлинг

Exhaust 11 illustrations ~6026 words

Fastener Tightening Specifications

ApplicationSpecification
MetricEnglish
Catalytic Converter-to-Exhaust Manifold Bolt/Nut (LZ4/LZ9)31 N.m23 lb ft
Exhaust Manifold Bolt (LZ4/LZ9)20 N.m15 lb ft
Exhaust Manifold Brace Bolt (L61)25 N.m18 lb ft
Exhaust Manifold Heat Shield Bolt (L61)23 N.m17 lb ft
Exhaust Manifold Heat Shield Bolt (LZ4/LZ9)10 N.m89 lb in
Exhaust Manifold Nut (L61)14 N.m10 lb ft
Exhaust Manifold Pipe-to-Muffler Nut (L61)30 N.m22 lb ft
Exhaust Manifold Pipe Nut (L61)35 N.m26 lb ft
Exhaust Pipe Heat Shield Nut10 N.m89 lb in
Heater Oxygen Sensor42 N.m31 lb ft
Heat Shield Nut10 N.m89 lb in
Left Catalytic Converter-to-Exhaust Manifold Nut (LZ4/LZ9)31 N.m23 lb ft
Left Catalytic Converter-to-Right Catalytic Converter Nut (LZ4/LZ9)31 N.m23 lb ft
Rear Catalytic Converter-to-Muffler Nut30 N.m22 lb ft

Fastener Tightening Specifications

Diagnostic Starting Point - Engine Exhaust

Begin the system diagnosis by reviewing the system Description and Operation. Reviewing the information will help you determine the correct symptom diagnostic procedure when a malfunction exists. It will also help you determine if the condition described by the customer is normal operation. Refer to Symptoms - Engine Exhaust in order to identify the correct procedure for diagnosing the system.

Symptoms - Engine Exhaust

  1. Review the Exhaust System Description and Operation in order to familiarize yourself with the system functions. Refer to «Exhaust System Description»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system__exhaust-system-description) .
  2. All diagnostics on a vehicle should follow a logical process. Strategy Based Diagnostics is a uniform approach for repairing all systems. The diagnostic flow is the place to start when repairs are necessary and may always be used in order to resolve a system problem. For a detailed explanation, refer to «Strategy Based Diagnosis»(/chevrolet/malibu/vi-2006-2008/remont/oem-general-information/#vehicle-diagnostic-information__strategy-based-diagnosis) .

Visual/Physical Inspection

  1. Inspect for aftermarket or non-OEM devices such as, but not including; tailpipe extensions, mufflers, and exhaust hangers. This could affect the operation and proper performance of the exhaust system.
  2. Verify the exact operating conditions under which the concern exists. Note factors such as engine RPM, engine temperature, engine load, and frequency of concern.
  3. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause any symptom.

Intermittent

Test the vehicle under the same conditions that the customer reported in order to verify the system is operating as designed.

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom

  1. Loss of power. Refer to «Restricted Exhaust»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) .
  2. Poor acceleration. Refer to «Restricted Exhaust»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) .
  3. Poor fuel economy. Refer to «Restricted Exhaust»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) .
  4. Exhaust hissing noise. Refer to «Exhaust Leakage»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system__exhaust-leakage) .
  5. Exhaust popping noise. Refer to «Exhaust Leakage»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system__exhaust-leakage) .
  6. Exhaust rattle noise. Refer to «Exhaust Noise»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system__exhaust-noise) .
  7. Loud exhaust noise. Refer to «Exhaust Noise»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system__exhaust-noise) .
  8. Exhaust buzz, groan, humm noise. Refer to «Exhaust Noise»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system__exhaust-noise) .

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. 3: The exhaust system has very low back pressure under normal conditions. If the exhaust system is restricted, a significant increase in the exhaust pressure is noticed on the J 35314-A Exhaust Back Pressure Gage. See «Special Tools»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system__special-tools) .Removing the heated oxygen sensor (HO2S) may set a DTC. When finishing this diagnostic table, be sure to clear all codes.
  2. 4: This step will isolate the catalytic converter from the remainder of the exhaust system.
StepActionValue(s)YesNo
1Did you verify the customers complaint?Go to Step 2
2Did you review the exhaust symptoms diagnostic information and perform the necessary inspections?Go to Step 3Go to Symptoms - Engine Exhaust
3CAUTION: Refer to HOT EXHAUST SYSTEM CAUTION . Remove the pre-catalyst HO2S. Refer to one of the following: Heated Oxygen Sensor 1 Replacement for the 2.2L engine. Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 or Heated Oxygen Sensor Replacement - Bank 2 Sensor 1 for the 3.5L engine. Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 or Heated Oxygen Sensor Replacement - Bank 2 Sensor 1 for the 3.9L engine. Install the J 35314-A in place of the HO2S. See Special Tools . Start and run the vehicle. Increase and monitor the engine speed at 2,500 RPM. Observe the exhaust system back pressure reading on the gage. Does the reading exceed the specified value?9 kPa (1.25 psi)Go to Step 4Go to Step 7
4Turn the engine OFF and place the ignition in the lock position. Remove the J 35314-A . See Special Tools . Install the pre-catalyst HO2S. Refer to one of the following: Heated Oxygen Sensor 1 Replacement for the 2.2L engine. Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 or Heated Oxygen Sensor Replacement - Bank 2 Sensor 1 for the 3.5L engine. Heated Oxygen Sensor Replacement - Bank 1 Sensor 1 or Heated Oxygen Sensor Replacement - Bank 2 Sensor 1 for the 3.9L engine. Remove the post-catalyst HO2S. Refer to one of the following: Heated Oxygen Sensor 2 Replacement for the 2.2L engine. Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 or Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 for the 3.5L engine. Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 or Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 for the 3.9L engine. Install the J 35314-A in place of the post HO2S. See Special Tools . Start the engine. Increase and monitor the engine speed at 2,500 RPM. Observe the exhaust system back pressure reading on the gage. Does the reading exceed the specified value?9 kPa (1.25 psi)Go to Step 5Go to Step 6
5Inspect the exhaust system for the following conditions: Damage in the exhaust pipe Debris in the exhaust pipe Muffler or resonator internal failure Two-layer exhaust pipe separation Did you find and correct the condition?Go to Step 7
6Replace the catalytic converter. Refer to Catalytic Converter Replacement - Left Side (LZ4) or Catalytic Converter Replacement - Left Side (LZ9) and/or Catalytic Converter Replacement - Right Side (LZ4) or Catalytic Converter Replacement - Right Side (LZ9) . Did you find and correct the condition?Go to Step 7
7Remove the J 35314-A . See Special Tools . Install the post-catalyst HO2S. Refer to one of the following: Heated Oxygen Sensor 2 Replacement for the 2.2L engine. Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 or Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 for the 3.5L engine. Heated Oxygen Sensor Replacement - Bank 1 Sensor 2 or Heated Oxygen Sensor Replacement - Bank 2 Sensor 2 for the 3.9L engine. Clear any codes. Road test the vehicle in order to verify the repair. Did you correct the condition?System OKGo to Step 2
CAUTION
Refer to HOT EXHAUST SYSTEM CAUTION .

Restricted Exhaust

Exhaust Leakage

ProblemAction
CAUTION: While engine is operating, the exhaust system will become extremely hot. To prevent burns avoid contacting a hot exhaust system. DEFINITION: An exhaust leak may show stains at the area of the leak. The leak may be felt by holding a hand close to the suspected areas or using a smoke pencil. The leak may make a popping or hissing noise.Refer to Symptoms - Engine Exhaust prior to beginning this table.
Misaligned or improperly installed exhaust system componentsAlign and tighten the components to the specifications. Refer to Fastener Tightening Specifications .
Exhaust leaks at the following connections: Exhaust manifold to pipe Flanges Pipe clampsTighten the components to the specifications. Refer to Fastener Tightening Specifications .
Seals or gaskets leaking. Exhaust manifold to cylinder head Exhaust pipes to exhaust manifold Catalytic converter connection EGR connections AIR connections to the exhaust manifold or cylinder headReplace the leaking seal or gasket. Refer to the affected components procedure for service.
Irregularities at the mating surfaces on the flange connectionsRepair as required or replace the affected component. Refer to the affected components procedure for service.
Exhaust manifold cracked or brokenReplace the exhaust manifold. Refer to Exhaust Manifold Replacement (L61) .
Exhaust system component connection welds leakingReplace the leaking component. Refer to the affected component's procedure for service.
Muffler or resonator, if equipped, damaged or leaking at the seamsReplace the affected muffler. Refer to Muffler Replacement (Sedan LS, LT, Maxx LT) or Muffler Replacement (Sedan LTZ, Maxx LTZ) or Muffler Replacement (Sedan SS, Maxx SS) .
CAUTION
While engine is operating, the exhaust system will become extremely hot. To prevent burns avoid contacting a hot exhaust system.

Exhaust Leakage

Exhaust Noise

ConditionAction
CAUTION: Refer to Hot Exhaust System Caution . DEFINITION: An audible or physical noise due to a faulty component or damaged components causing a loose or misaligned exhaust system resulting in a rattle or vibration noise, i.e. buzz, groan, hum.Refer to Symptoms - Engine Exhaust prior to beginning this table.
Popping or hissing noiseExhaust leak-Refer to Exhaust Leakage .
Loud exhaustCompare to a known good vehicle. Inspect for a damaged or failed muffle. Replace the faulty muffler. Refer to Muffler Replacement (Sedan LS, LT, Maxx LT) or Muffler Replacement (Sedan LTZ, Maxx LTZ) or Muffler Replacement (Sedan SS, Maxx SS) .
External rattle or vibration noiseInspect for a bent or loose hanger, loose heat shield, or loose clamp. Inspect for a exhaust pipe causing interference. Repair or replace the affected component. Refer to the affected component's service procedure.
Internal rattleTest the components by tapping with a rubber mallet to confirm a rattle. Replace the faulty catalytic converter, or muffler. Refer to one of the following procedures: Catalytic Converter Replacement - Left Side (LZ4) Catalytic Converter Replacement - Left Side (LZ9) Catalytic Converter Replacement - Right Side (LZ4) Catalytic Converter Replacement - Right Side (LZ9) Muffler Replacement (Sedan LS, LT, Maxx LT) Muffler Replacement (Sedan LTZ, Maxx LTZ) Muffler Replacement (Sedan SS, Maxx SS)
CAUTION
Refer to Hot Exhaust System Caution .

Exhaust Noise

Removal Procedure

Note. The oxygen sensor uses a permanently attached pigtail and connector. Do not remove the pigtail from the oxygen sensor. Damage to or removal of the pigtail connector could affect proper operation of the oxygen sensor.

Note. The use of excessive force may damage the threads in the exhaust manifold/pipe.

IMPORTANTThe in-line connector and louvered end must be kept clear of grease, dirt or other contaminants. Avoid using cleaning solvents of any type. DO NOT drop or roughly handle the HO2S.
IMPORTANTThe HO2S may be difficult to remove when the engine temperature is less than 48°C (120°F)
  1. Remove the connector position assurance (CPA) retainer (1).
  2. Disconnect the engine wiring harness electrical connector (4) from the heated oxygen sensor (HO2S) electrical connector (3).
  3. Remove the HO2S electrical connector rosebud clip (2) from the thermostat housing.
  4. Remove the HO2S (1).
  5. Remove the fuel feed pipe clips (2) from the fuel feed pipe bracket.
  6. Remove the exhaust manifold heat shield bolts (2).
  7. Remove the fuel feed pipe bracket (1).
  8. Remove the exhaust manifold heat shield.
  9. Remove the exhaust manifold pipe. Refer to «Exhaust Manifold Pipe Replacement (L61)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) .
  10. Remove the upper exhaust manifold brace bolt.
  11. Remove and discard the exhaust manifold nuts.
  12. Remove the exhaust manifold/catalytic converter assembly.
  13. Remove and discard the exhaust manifold gasket.

Scheme 1

Scheme 1: Installation Procedure
Scheme 1: Installation Procedure

Scheme 2

Scheme 2
Scheme 2
  1. Install a NEW exhaust manifold gasket on the studs.
  2. Install the exhaust manifold/catalytic converter assembly.
  3. Install the NEW exhaust manifold nuts finger tight. NOTE: Refer to «Fastener Notice»(/chevrolet/malibu/vi-2006-2008/remont/oem-general-information/#warnings-and-cautions__fastener-notice) .
  4. Install the upper exhaust manifold brace bolt. Tighten: Tighten the bolt to 25 N.m (18 lb ft).
  5. Tighten the exhaust manifold nuts in the sequence shown. Tighten: Tighten the nuts to 14 N.m (10 lb ft).
  6. Install the exhaust manifold pipe. Refer to «Exhaust Manifold Pipe Replacement (L61)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) .
  7. Position the exhaust manifold heat shield.
  8. Position the fuel feed pipe bracket (1).
  9. Install the exhaust manifold heat shield bolts. Tighten: Tighten the bolts to 23 N.m (17 lb ft).
  10. Install the fuel feed pipe clips (2) to the fuel feed pipe bracket. IMPORTANT: A special anti-seize compound is used on the HO2S threads. The compound consists of graphite suspended in fluid and glass beads. The graphite will burn away, but the glass beads will remain, making the sensor easier to remove. New or service sensors will already have the compound applied to the threads. If a sensor is removed from an engine and is to be reinstalled, the threads must have anti-seize compound applied before the reinstallation.
  11. Coat the threads of the HO2S with anti-seize compound GM P/N 12377953 or equivalent, if necessary.
  12. Install the HO2S. Tighten: Tighten the sensor to 42 N.m (31 lb ft).
  13. Connect the engine wiring harness electrical connector (4) to the HO2S electrical connector (3).
  14. Install the HO2S electrical connector rosebud clip (2) to the thermostat housing.
  15. Install the CPA retainer (1).

Tools Required

J 39194-B Heated Oxygen Sensor Wrench. See Special Tools .

Note. The oxygen sensor uses a permanently attached pigtail and connector. Do not remove the pigtail from the oxygen sensor. Damage to or removal of the pigtail connector could affect proper operation of the oxygen sensor.

Note. The use of excessive force may damage the threads in the exhaust manifold/pipe.

IMPORTANTThe in-line connector and louvered end must be kept clear of grease, dirt or other contaminants. Avoid using cleaning solvents of any type. DO NOT drop or roughly handle the heated oxygen sensor (HO2S).
IMPORTANTThe HO2S may be difficult to remove when the engine temperature is less than 48°C (120°F)
  1. Remove the air intake duct. Refer to «Air Cleaner Inlet Duct Replacement»(/chevrolet/malibu/vi-2006-2008/remont/testing-diagnostics/#engine-controls-fuel-35l-introduction-2-of-2) .
  2. Remove the connector position assurance (CPA) retainer (5).
  3. Disconnect the engine wiring harness electrical connector (4) from the HO2S electrical connector (3).
  4. Remove the HO2S electrical connector rosebud clip from the oil level indicator tube tab.
  5. Remove the HO2S using the J 39194-B . See «Special Tools»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system__special-tools) .
  6. Remove the exhaust manifold heat shield bolts and shield.
  7. Remove the upper exhaust manifold bolts.
  8. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vi-2006-2008/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) .
  9. Remove the left catalytic converter. Refer to «Catalytic Converter Replacement - Left Side (LZ4)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) or «Catalytic Converter Replacement - Left Side (LZ9)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) .
  10. Remove the lower exhaust manifold bolts.
  11. Remove the exhaust manifold.
  12. Remove and discard the exhaust manifold gasket.

Scheme 3

Scheme 3: Installation Procedure
Scheme 3: Installation Procedure
  1. Install a NEW exhaust manifold gasket onto the cylinder head studs.
  2. Install the exhaust manifold. NOTE: Refer to «Fastener Notice»(/chevrolet/malibu/vi-2006-2008/remont/oem-general-information/#warnings-and-cautions__fastener-notice) .
  3. Install the exhaust manifold bolts. Tighten: Tighten the bolts to 20 N.m (15 lb ft).
  4. Install the left catalytic converter. Refer to «Catalytic Converter Replacement - Left Side (LZ4)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) or «Catalytic Converter Replacement - Left Side (LZ9)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) .
  5. Lower the vehicle.
  6. Install the exhaust manifold heat shield and bolts. Tighten: Tighten the bolts to 10 N.m (89 lb in). IMPORTANT: A special anti-seize compound is used on the HO2S threads. The compound consists of graphite suspended in fluid and glass beads. The graphite will burn away, but the glass beads will remain, making the sensor easier to remove. New or service sensors will already have the compound applied to the threads. If a sensor is removed from an engine and is to be reinstalled, the threads must have anti-seize compound applied before the reinstallation.
  7. Coat the threads of the HO2S with anti-seize compound GM P/N 12377953 or equivalent, if necessary.
  8. Install the HO2S using J 39194-B . See «Special Tools»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system__special-tools) . Tighten: Tighten the sensor to 42 N.m (31 lb ft).
  9. Connect the engine wiring harness electrical connector (4) to the HO2S electrical connector (3).
  10. Install the HO2S electrical connector rosebud clip to the oil level indicator tube tab.
  11. Install the CPA retainer (5).
  12. Install the air intake duct. Refer to «Air Cleaner Inlet Duct Replacement»(/chevrolet/malibu/vi-2006-2008/remont/testing-diagnostics/#engine-controls-fuel-35l-introduction-2-of-2) .

J 39194-B Heated Oxygen Sensor Wrench. See Special Tools .

Scheme 4

Scheme 4: Removal Procedure
Scheme 4: Removal Procedure
  1. Remove the air cleaner outlet duct. Refer to «Air Cleaner Outlet Duct Replacement»(/chevrolet/malibu/vi-2006-2008/remont/testing-diagnostics/#engine-controls-fuel-39l-introduction-2-of-2) .
  2. Remove the connector position assurance (CPA) retainer (5).
  3. Disconnect the heated oxygen sensor (HO2S) electrical connector (4).
  4. Remove the HO2S clip (3) from the oil level indicator tube bracket. IMPORTANT: The HO2S uses a permanently attached pigtail and connector. This pigtail should not be removed from the sensor. Damage or removal of the pigtail or connector will affect proper operation of the sensor.
  5. Remove the HO2S using the J 39194-B . See «Special Tools»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system__special-tools) .
  6. Remove the exhaust manifold heat shield bolts.
  7. Remove the exhaust manifold heat shield.
  8. Remove the upper exhaust manifold bolts.
  9. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vi-2006-2008/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) .
  10. Remove the left catalytic converter. Refer to «Catalytic Converter Replacement - Left Side (LZ4)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) or «Catalytic Converter Replacement - Left Side (LZ9)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) .
  11. Remove the lower exhaust manifold bolts.
  12. Remove the exhaust manifold.
  13. Remove and discard the exhaust manifold gasket.

Installation Procedure

  1. Install a NEW exhaust manifold gasket onto the cylinder head studs.
  2. Install the exhaust manifold. NOTE: Refer to «Fastener Notice»(/chevrolet/malibu/vi-2006-2008/remont/oem-general-information/#warnings-and-cautions__fastener-notice) .
  3. Install the exhaust manifold bolts. Tighten: Tighten the bolts to 20 N.m (15 lb ft).
  4. Install the left catalytic converter. Refer to «Catalytic Converter Replacement - Left Side (LZ4)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) or «Catalytic Converter Replacement - Left Side (LZ9)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) .
  5. Lower the vehicle.
  6. Install the exhaust manifold heat shield.
  7. Install the exhaust manifold heat shield bolts. Tighten: Tighten the bolts to 10 N.m (89 lb in). IMPORTANT: Whenever the oxygen sensor is removed, coat the threads with nickel-based anti-seize compound, such as GM P/N 5613695, or equivalent.
  8. Install the HO2S using J 39194-B . See «Special Tools»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system__special-tools) . Tighten: Tighten the sensor to 42 N.m (31 lb ft).
  9. Connect the HO2S electrical connector (1).
  10. Install the CPA retainer (2).
  11. Install the HO2S clip (3) to the oil level indicator tube bracket.
  12. Install the air cleaner outlet duct. Refer to «Air Cleaner Outlet Duct Replacement»(/chevrolet/malibu/vi-2006-2008/remont/testing-diagnostics/#engine-controls-fuel-39l-introduction-2-of-2) .

J 39194-B Heated Oxygen Sensor Socket. See Special Tools .

Note. The oxygen sensor uses a permanently attached pigtail and connector. Do not remove the pigtail from the oxygen sensor. Damage to or removal of the pigtail connector could affect proper operation of the oxygen sensor.

Note. The use of excessive force may damage the threads in the exhaust manifold/pipe.

IMPORTANTThe in-line connector and louvered end must be kept clear of grease, dirt or other contaminants. Avoid using cleaning solvents of any type. DO NOT drop or roughly handle the heated oxygen sensor (HO2S).
IMPORTANTThe HO2S may be difficult to remove when the engine temperature is less than 48°C (120°F)
  1. Remove the generator. Refer to «Generator Replacement (L61)»(/chevrolet/malibu/vi-2006-2008/remont/charging-system/#battery-charging-system-and-starting-system) or «Generator Replacement (LZ4)»(/chevrolet/malibu/vi-2006-2008/remont/charging-system/#battery-charging-system-and-starting-system) or «Generator Replacement (LZ9)»(/chevrolet/malibu/vi-2006-2008/remont/charging-system/#battery-charging-system-and-starting-system) .
  2. Remove the connector position assurance (CPA) retainer (3).
  3. Disconnect the engine wiring harness electrical connector (2) from the HO2S electrical connector.
  4. Remove the HO2S electrical connector rosebud clip (1) from the ignition coil bracket.
  5. Remove the HO2S using the J 39194-B . See «Special Tools»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system__special-tools) .
  6. Remove the exhaust manifold heat shield bolts and shield.
  7. Remove the upper exhaust manifold bolts.
  8. Remove the right catalytic converter. Refer to «Catalytic Converter Replacement - Right Side (LZ4)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) or «Catalytic Converter Replacement - Right Side (LZ9)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) .
  9. Remove the lower exhaust manifold bolts.
  10. Remove the exhaust manifold.
  11. Remove and discard the exhaust manifold gasket.

Scheme 5

Scheme 5: Installation Procedure
Scheme 5: Installation Procedure
  1. Install a NEW exhaust manifold gasket onto the cylinder head studs.
  2. Install the exhaust manifold. NOTE: Refer to «Fastener Notice»(/chevrolet/malibu/vi-2006-2008/remont/oem-general-information/#warnings-and-cautions__fastener-notice) .
  3. Install the exhaust manifold bolts. Tighten: Tighten the bolts to 20 N.m (15 lb ft).
  4. Install the right catalytic converter. Refer to «Catalytic Converter Replacement - Right Side (LZ4)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) or «Catalytic Converter Replacement - Right Side (LZ9)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) .
  5. Install the exhaust manifold heat shield and bolts. Tighten: Tighten the bolts to 10 N.m (89 lb in). IMPORTANT: A special anti-seize compound is used on the HO2S threads. The compound consists of graphite suspended in fluid and glass beads. The graphite will burn away, but the glass beads will remain, making the sensor easier to remove. New or service sensors will already have the compound applied to the threads. If a sensor is removed from an engine and is to be reinstalled, the threads must have anti-seize compound applied before the reinstallation.
  6. Coat the threads of the HO2S with anti-seize compound GM P/N 12377953 or equivalent, if necessary.
  7. Install the HO2S using J 39194-B . See «Special Tools»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system__special-tools) . Tighten: Tighten the sensor to 42 N.m (31 lb ft).
  8. Connect the engine wiring harness electrical connector (2) to the HO2S electrical connector.
  9. Install the CPA retainer (3).
  10. Install the HO2S electrical connector rosebud clip (1) to the ignition coil bracket.
  11. Install the generator. Refer to «Generator Replacement (L61)»(/chevrolet/malibu/vi-2006-2008/remont/charging-system/#battery-charging-system-and-starting-system) or «Generator Replacement (LZ4)»(/chevrolet/malibu/vi-2006-2008/remont/charging-system/#battery-charging-system-and-starting-system) or «Generator Replacement (LZ9)»(/chevrolet/malibu/vi-2006-2008/remont/charging-system/#battery-charging-system-and-starting-system) .

J 39194-B Heated Oxygen Sensor Wrench. See Special Tools .

  1. Remove the generator. Refer to «Generator Replacement (L61)»(/chevrolet/malibu/vi-2006-2008/remont/charging-system/#battery-charging-system-and-starting-system) or «Generator Replacement (LZ4)»(/chevrolet/malibu/vi-2006-2008/remont/charging-system/#battery-charging-system-and-starting-system) or «Generator Replacement (LZ9)»(/chevrolet/malibu/vi-2006-2008/remont/charging-system/#battery-charging-system-and-starting-system) .
  2. Remove the connector position assurance (CPA) retainer (2).
  3. Disconnect the heated oxygen sensor (HO2S) electrical connector (1).
  4. Remove the HO2S clip from the ignition control module bracket. IMPORTANT: The HO2S uses a permanently attached pigtail and connector. This pigtail should not be removed from the sensor. Damage or removal of the pigtail or connector will affect proper operation of the sensor.
  5. Remove the HO2S using the J 39194-B . See «Special Tools»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system__special-tools) .
  6. Remove the exhaust manifold shield bolts.
  7. Remove the exhaust manifold shield.
  8. Remove the upper exhaust manifold bolts.
  9. Remove the right catalytic converter. Refer to «Catalytic Converter Replacement - Right Side (LZ4)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) or «Catalytic Converter Replacement - Right Side (LZ9)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) .
  10. Remove the lower exhaust manifold bolt.
  11. Remove the exhaust manifold.
  12. Remove and discard the exhaust manifold gasket.
  1. Install a NEW exhaust manifold gasket onto the cylinder head studs. NOTE: Refer to «Fastener Notice»(/chevrolet/malibu/vi-2006-2008/remont/oem-general-information/#warnings-and-cautions__fastener-notice) .
  2. Install the exhaust manifold.
  3. Install the exhaust manifold bolts. Tighten: Tighten the bolts to 20 N.m (15 lb ft).
  4. Install the right catalytic converter. Refer to «Catalytic Converter Replacement - Right Side (LZ4)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) or «Catalytic Converter Replacement - Right Side (LZ9)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) .
  5. Install the exhaust manifold shield.
  6. Install the exhaust manifold shield bolts. Tighten: Tighten the bolts to 10 N.m (89 lb in). IMPORTANT: Whenever the oxygen sensor is removed, coat the threads with nickel-based anti-seize compound such as GM P/N 5613695, or equivalent.
  7. Install the HO2S using J 39194-B . See «Special Tools»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system__special-tools) . Tighten: Tighten the sensor to 42 N.m (31 lb ft).
  8. Connect the HO2S electrical connector (1).
  9. Install the CPA retainer (2).
  10. Install the HO2S clip to the ignition control module bracket.
  11. Install the generator. Refer to «Generator Replacement (L61)»(/chevrolet/malibu/vi-2006-2008/remont/charging-system/#battery-charging-system-and-starting-system) or «Generator Replacement (LZ4)»(/chevrolet/malibu/vi-2006-2008/remont/charging-system/#battery-charging-system-and-starting-system) or «Generator Replacement (LZ9)»(/chevrolet/malibu/vi-2006-2008/remont/charging-system/#battery-charging-system-and-starting-system) .

J 39194 Oxygen Sensor Wrench

Note. The use of excessive force may damage the threads in the exhaust manifold/pipe.

IMPORTANTThe in-line connector and louvered end must be kept clear of grease, dirt or other contaminants. Avoid using cleaning solvents of any type. DO NOT drop or roughly handle the HO2S.
IMPORTANTThe HO2S may be difficult to remove when the engine temperature is less than 48°C (120°F)

Scheme 6

Scheme 6
Scheme 6
  1. Raise and support the vehicle. Refer «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vi-2006-2008/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) .
  2. Remove the connector position assurance (CPA) retainer (1).
  3. Disconnect the heated oxygen sensor (HO2S) electrical connector (2). NOTE: The oxygen sensor uses a permanently attached pigtail and connector. Do not remove the pigtail from the oxygen sensor. Damage to or removal of the pigtail connector could affect proper operation of the oxygen sensor.
  4. Using the J 39194 , remove the HO2S.
  5. Remove the exhaust manifold pipe to muffler nuts.
  6. Remove the exhaust manifold/catalytic converter to exhaust manifold pipe nuts.
  7. Remove the first muffler hanger insulator.
  8. Gently pull back and separate the muffler from the exhaust manifold pipe studs.
  9. Remove the exhaust manifold pipe.
  1. Install the exhaust manifold pipe to the exhaust manifold/catalytic converter.
  2. Gently pull back and install the exhaust manifold pipe studs to the muffler.
  3. Install the first muffler hanger insulator. NOTE: Refer to «Fastener Notice»(/chevrolet/malibu/vi-2006-2008/remont/oem-general-information/#warnings-and-cautions__fastener-notice) .
  4. Install the exhaust manifold/catalytic converter to exhaust manifold pipe nuts. Tighten: Tighten the nuts to 35 N.m (26 lb ft).
  5. Install the exhaust manifold pipe to muffler nuts. Tighten: Tighten the nuts to 30 N.m (22 lb ft). IMPORTANT: A special anti-seize compound is used on the HO2S threads. The compound consists of graphite suspended in fluid and glass beads. The graphite will burn away, but the glass beads will remain, making the sensor easier to remove. New or service sensors will already have the compound applied to the threads. If a sensor is removed from an engine and is to be reinstalled, the threads must have anti-seize compound applied before the reinstallation.
  6. If reinstalling the old HO2S, coat the threads with anti-seize compound GM P/N 12377953 or equivalent.
  7. Using the J 39194 , install the HO2S. Tighten: Tighten the sensor to 42 N.m (30 lb ft).
  8. Connect the HO2S electrical connector (2).
  9. Install the CPA retainer (1).
  10. Lower the vehicle.

J 39194-B Heated Oxygen Sensor Wrench. See Special Tools .

Note. The oxygen sensor uses a permanently attached pigtail and connector. Do not remove the pigtail from the oxygen sensor. Damage to or removal of the pigtail connector could affect proper operation of the oxygen sensor.

Note. The use of excessive force may damage the threads in the exhaust manifold/pipe.

IMPORTANTThe in-line connector and louvered end must be kept clear of grease, dirt or other contaminants. Avoid using cleaning solvents of any type. DO NOT drop or roughly handle the HO2S.
IMPORTANTThe HO2S may be difficult to remove when the engine temperature is less than 48°C (120°F)
  1. Remove the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/chevrolet/malibu/vi-2006-2008/remont/testing-diagnostics/#engine-controls-fuel-35l-introduction-2-of-2) .
  2. Remove the connector position assurance (CPA) retainer (5).
  3. Disconnect the engine wiring harness electrical connector (4) from the heated oxygen sensor (HO2S) electrical connector (3).
  4. Remove the HO2S electrical connector rosebud clip from the oil level indicator tube tab.
  5. Remove the exhaust manifold heat shield bolts and shield.
  6. Remove the left (front) catalytic converter nuts (1) at the exhaust manifold.
  7. Remove the muffler assembly. Refer to «Muffler Replacement (Sedan LS, LT, Maxx LT)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) or «Muffler Replacement (Sedan LTZ, Maxx LTZ)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) or «Muffler Replacement (Sedan SS, Maxx SS)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) .
  8. Remove the lower right HO2S electrical connector CPA retainer (1).
  9. Disconnect the rear HO2S electrical connector from the engine wiring harness electrical connector (2).
  10. Remove the lower left HO2S CPA retainer (3).
  11. Disconnect the front engine wiring harness electrical connector (1) from the HO2S electrical connector.
  12. Remove the lower right and left HO2S's (1, 2) using the J 39194-B . See «Special Tools»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system__special-tools) .
  13. Remove the left (front) catalytic converter to right (rear) catalytic converter nuts (3).
  14. Remove the right (rear) catalytic converter bolt (5) and nuts (1) at the exhaust manifold.
  15. Remove and discard the gasket (6).
  16. Remove the right (rear) catalytic converter (2).
  17. Remove the left (front) catalytic converter (4).
  18. Remove and discard the left (front) catalytic converter to manifold gasket.
  19. Inspect the catalytic converter-to-exhaust manifold flange. Catalytic Converter to Manifold Flange Warpage: Service Limit: 0.7 mm (0.028 in) max. Standard: 0.7 mm (0.028 in) max.

Scheme 7

Scheme 7: Installation Procedure
Scheme 7: Installation Procedure
  1. Install a NEW gasket to the left (front) catalytic converter studs.
  2. Install the left (front) catalytic converter (4).
  3. Install a NEW gasket (6) tooth right (rear) catalytic converter studs.
  4. Install the right (rear) catalytic converter (2). NOTE: Refer to «Fastener Notice»(/chevrolet/malibu/vi-2006-2008/remont/oem-general-information/#warnings-and-cautions__fastener-notice) .
  5. Install the right (rear) catalytic converter bolt (5) and nuts (1) at the exhaust manifold. Tighten: Tighten the bolt/nuts to 31 N.m (23 lb ft).
  6. Install the left (front) catalytic converter to right (rear) catalytic converter nuts (3). Tighten: Tighten the nuts to 31 N.m (23 lb ft). IMPORTANT: A special anti-seize compound is used on the HO2S threads. The compound consists of graphite suspended in fluid and glass beads. The graphite will burn away, but the glass beads will remain, making the sensor easier to remove. New or service sensors will already have the compound applied to the threads. If a sensor is removed from an engine and is to be reinstalled, the threads must have anti-seize compound applied before the reinstallation.
  7. If reinstalling the old HO2S, coat the threads with anti-seize compound GM P/N 12377953 or equivalent.
  8. Install the lower right and left HO2S's (1, 2) using the J 39194-B . See «Special Tools»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system__special-tools) . Tighten: Tighten the sensors to 42 N.m (31 lb ft).
  9. Connect the front engine wiring harness electrical connector (1) to the HO2S electrical connector.
  10. Install the lower left HO2S CPA retainer (3).
  11. Connect the rear HO2S electrical connector to the engine wiring harness electrical connector (2).
  12. Install the lower right HO2S electrical connector CPA retainer (1).
  13. Remove the muffler assembly. Refer to «Muffler Replacement (Sedan LS, LT, Maxx LT)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) or «Muffler Replacement (Sedan LTZ, Maxx LTZ)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) or «Muffler Replacement (Sedan SS, Maxx SS)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) .
  14. Install the left (front) catalytic converter nuts (1) at the exhaust manifold. Tighten: Tighten the nuts to 31 N.m (23 lb ft).
  15. Remove the exhaust manifold heat shield bolts and shield. Tighten: Tighten the bolts to 10 N.m (89 lb in).
  16. Connect the engine wiring harness electrical connector (4) to the HO2S electrical connector (3).
  17. Install the CPA retainer (5).
  18. Install the HO2S electrical connector rosebud clip to the oil level indicator tube tab.
  19. Install the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/chevrolet/malibu/vi-2006-2008/remont/testing-diagnostics/#engine-controls-fuel-35l-introduction-2-of-2) .

J 39194-B Heated Oxygen Sensor Wrench. See Special Tools .

Note. The oxygen sensor uses a permanently attached pigtail and connector. Do not remove the pigtail from the oxygen sensor. Damage to or removal of the pigtail connector could affect proper operation of the oxygen sensor.

Note. The use of excessive force may damage the threads in the exhaust manifold/pipe.

IMPORTANTThe in-line connector and louvered end must be kept clear of grease, dirt or other contaminants. Avoid using cleaning solvents of any type. DO NOT drop or roughly handle the HO2S.
IMPORTANTThe HO2S may be difficult to remove when the engine temperature is less than 48°C (120°F)
  1. Remove the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/chevrolet/malibu/vi-2006-2008/remont/testing-diagnostics/#engine-controls-fuel-35l-introduction-2-of-2) .
  2. Remove the connector position assurance (CPA) retainer (5).
  3. Disconnect the heated oxygen sensor (HO2S) electrical connector (4).
  4. Remove the HO2S clip (3) from the oil level indicator tube bracket.
  5. Remove the exhaust manifold heat shield bolts.
  6. Remove the exhaust manifold heat shield.
  7. Remove the left (front) catalytic converter nuts (1) at the exhaust manifold.
  8. Remove the muffler assembly. Refer to «Muffler Replacement (Sedan LS, LT, Maxx LT)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) , «Muffler Replacement (Sedan LTZ, Maxx LTZ)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) or «Muffler Replacement (Sedan SS, Maxx SS)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) .
  9. Remove the lower right heated oxygen sensor HO2S connector position assurance (CPA) retainer (1).
  10. Disconnect the rear HO2S electrical connector (2).
  11. Remove the lower left HO2S CPA retainer (1).
  12. Disconnect the front HO2S electrical connector (2).
  13. Remove the lower right and left HO2S (1, 2) using the J 39194-B . See «Special Tools»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system__special-tools) .
  14. Remove the left (front) catalytic converter to right (rear) catalytic converter nuts (3).
  15. Remove the right (rear) catalytic converter bolt (5) and nuts (1) at the exhaust manifold.
  16. Remove and discard the gasket (6).
  17. Remove the right (rear) catalytic converter (2).
  18. Remove the left (front) catalytic converter (4).
  19. Remove and discard the left (front) catalytic converter to manifold gasket.
  20. Inspect the catalytic converter-to-exhaust manifold flange. Catalytic Converter to Manifold Flange Warpage: Service Limit: 0.7 mm (0.028 in) max. Standard: 0.7 mm (0.028 in) max.
  1. Install a NEW gasket to the left (front) catalytic converter studs.
  2. Install the left (front) catalytic converter (4).
  3. Install a NEW gasket (6) to the right (rear) catalytic converter studs.
  4. Install the right (rear) catalytic converter (2). NOTE: Refer to «Fastener Notice»(/chevrolet/malibu/vi-2006-2008/remont/oem-general-information/#warnings-and-cautions__fastener-notice) .
  5. Install the right (rear) catalytic converter bolt (5) and nuts (1) at the exhaust manifold. Tighten: Tighten the bolt and nuts to 31 N.m (23 lb ft).
  6. Install the left (front) catalytic converter to right (rear) catalytic converter nuts (3). Tighten: Tighten the nuts to 31 N.m (23 lb ft). IMPORTANT: A special anti-seize compound is used on the HO2S threads. The compound consists of liquid graphite and glass beads. The graphite tends to burn away but the beads remain, making the sensor easier the remove. New, or service replacement sensors already have the compound applied to the threads. If the sensor is removed from an exhaust component and if for any reason the sensor is to be reinstalled, the threads must be have anti-seize compound applied before the reinstallation.
  7. If reinstalling the old HO2S, coat the threads with anti-seize compound GM P/N 12377953 or equivalent.
  8. Install the lower right and left HO2S (1, 2) using the J 39194-B . See «Special Tools»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system__special-tools) . Tighten: Tighten the sensor to 42 N.m (31 lb ft).
  9. Connect the lower left HO2S electrical connector (1).
  10. Install the lower left HO2S CPA retainer (2).
  11. Connect the lower right HO2S electrical connector (2).
  12. Install the lower right HO2S CPA retainer (1).
  13. Install the muffler assembly. Refer to «Muffler Replacement (Sedan LS, LT, Maxx LT)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) or «Muffler Replacement (Sedan LTZ, Maxx LTZ)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) or «Muffler Replacement (Sedan SS, Maxx SS)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) .
  14. Install the left (front) catalytic converter nuts (1) at the exhaust manifold. Tighten: Tighten the nuts to 31 N.m (23 lb ft).
  15. Install the exhaust manifold heat shield.
  16. Install the exhaust manifold heat shield bolts. Tighten: Tighten the bolts to 10 N.m (89 lb in).
  17. Connect the HO2S electrical connector (4).
  18. Install the CPA retainer (5).
  19. Install the HO2S clip (3) to the oil level indicator tube bracket.
  20. Install the air cleaner assembly. Refer to «Air Cleaner Assembly Replacement»(/chevrolet/malibu/vi-2006-2008/remont/testing-diagnostics/#engine-controls-fuel-35l-introduction-2-of-2) .
  21. Perform the engine mount position adjustment procedure. Refer to «Engine Mount Position Adjustment»(/chevrolet/malibu/vi-2006-2008/remont/mechanical/#engine-mechanical-22l-l61__engine-mount-position-adjustment) .

J 39194-B Heated Oxygen Sensor Wrench. See Special Tools .

Note. The oxygen sensor uses a permanently attached pigtail and connector. Do not remove the pigtail from the oxygen sensor. Damage to or removal of the pigtail connector could affect proper operation of the oxygen sensor.

Note. The use of excessive force may damage the threads in the exhaust manifold/pipe.

IMPORTANTThe in-line connector and louvered end must be kept clear of grease, dirt or other contaminants. Avoid using cleaning solvents of any type. DO NOT drop or roughly handle the HO2S.
IMPORTANTThe HO2S may be difficult to remove when the engine temperature is less than 48°C (120°F).
  1. Remove the muffler assembly. Refer to «Muffler Replacement (Sedan LS, LT, Maxx LT)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) or «Muffler Replacement (Sedan LTZ, Maxx LTZ)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) or «Muffler Replacement (Sedan SS, Maxx SS)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) .
  2. Remove the rear stabilizer shaft. Refer to «Stabilizer Shaft Replacement (Base Sedan)»(/chevrolet/malibu/vi-2006-2008/remont/suspension-rear/#rear-suspension-system) or «Stabilizer Shaft Replacement (Extended Sedan)»(/chevrolet/malibu/vi-2006-2008/remont/suspension-rear/#rear-suspension-system) .
  3. Remove the connector position assurance (CPA) retainer (3).
  4. Disconnect the lower right heated oxygen sensor (HO2S) electrical connector from the engine wiring harness electrical connector (2).
  5. Remove the lower right HO2S (2) using the J 39194-B . See «Special Tools»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system__special-tools) .
  6. Remove the left (front) catalytic converter to right (rear) catalytic converter nuts (3).
  7. Remove the right (rear) catalytic converter bolt (5) and nuts (1) at the exhaust manifold.
  8. Remove the right catalytic converter (2).
  9. Remove and discard the gasket (6).
  10. Inspect the catalytic converter-to-exhaust manifold flange. Catalytic Converter to Manifold Flange Warpage: Service Limit: 0.7 mm (0.028 in) max. Standard: 0.7 mm (0.028 in) max.
  1. Install a NEW gasket (6) to the catalytic converter.
  2. Install the right (rear) catalytic converter (2). NOTE: Refer to «Fastener Notice»(/chevrolet/malibu/vi-2006-2008/remont/oem-general-information/#warnings-and-cautions__fastener-notice) .
  3. Install the right (rear) catalytic converter bolt (5) and nuts (1) at the exhaust manifold. Tighten: Tighten the bolt/nuts to 31 N.m (23 lb ft).
  4. Install the left (front) catalytic converter to right (rear) catalytic converter nuts (3). Tighten: Tighten the nuts to 31 N.m (23 lb ft). IMPORTANT: A special anti-seize compound is used on the HO2S threads. The compound consists of graphite suspended in fluid and glass beads. The graphite will burn away, but the glass beads will remain, making the sensor easier to remove. New or service sensors will already have the compound applied to the threads. If a sensor is removed from an engine and is to be reinstalled, the threads must have anti-seize compound applied before the reinstallation.
  5. If reinstalling the old HO2S, coat the threads with anti-seize compound GM P/N 12377953 or equivalent.
  6. Install the lower right HO2S (2) using the J 39194-B . See «Special Tools»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system__special-tools) . Tighten: Tighten the sensor to 42 N.m (31 lb ft).
  7. Connect the lower right HO2S electrical connector to the engine wiring harness electrical connector (2).
  8. Install the CPA retainer (3).
  9. Install the rear stabilizer shaft. Refer to «Stabilizer Shaft Replacement (Base Sedan)»(/chevrolet/malibu/vi-2006-2008/remont/suspension-rear/#rear-suspension-system) or «Stabilizer Shaft Replacement (Extended Sedan)»(/chevrolet/malibu/vi-2006-2008/remont/suspension-rear/#rear-suspension-system) .
  10. Install the muffler assembly. Refer to «Muffler Replacement (Sedan LS, LT, Maxx LT)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) or «Muffler Replacement (Sedan LTZ, Maxx LTZ)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) or «Muffler Replacement (Sedan SS, Maxx SS)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) .

J 39194-B Heated Oxygen Sensor Wrench. See Special Tools .

Note. The oxygen sensor uses a permanently attached pigtail and connector. Do not remove the pigtail from the oxygen sensor. Damage to or removal of the pigtail connector could affect proper operation of the oxygen sensor.

Note. The use of excessive force may damage the threads in the exhaust manifold/pipe.

IMPORTANTThe in-line connector and louvered end must be kept clear of grease, dirt or other contaminants. Avoid using cleaning solvents of any type. DO NOT drop or roughly handle the HO2S.
IMPORTANTThe HO2S may be difficult to remove when the engine temperature is less than 48°C (120°F).
  1. Remove the muffler assembly. Refer to «Muffler Replacement (Sedan LS, LT, Maxx LT)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) or «Muffler Replacement (Sedan LTZ, Maxx LTZ)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) or «Muffler Replacement (Sedan SS, Maxx SS)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) .
  2. Remove the rear stabilizer shaft. Refer to «Stabilizer Shaft Replacement (Base Sedan)»(/chevrolet/malibu/vi-2006-2008/remont/suspension-rear/#rear-suspension-system) or «Stabilizer Shaft Replacement (Extended Sedan)»(/chevrolet/malibu/vi-2006-2008/remont/suspension-rear/#rear-suspension-system) .
  3. Remove the connector position assurance (CPA) retainer (1).
  4. Disconnect the lower right heated oxygen sensor (HO2S) electrical connector (2).
  5. Remove the lower right HO2S (2) using the J 39194-B . See «Special Tools»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system__special-tools) .
  6. Remove the left (front) catalytic converter to right (rear) catalytic converter nuts (3).
  7. Remove the right (rear) catalytic converter bolt (5) and nuts (1) at the exhaust manifold.
  8. Remove the right catalytic converter (2).
  9. Remove and discard the gasket (6).
  10. Inspect the catalytic converter-to-exhaust manifold flange. Catalytic Converter to Manifold Flange Warpage: Service Limit: 0.7 mm (0.028 in) max. Standard: 0.7 mm (0.028 in) max.
  1. Install a NEW gasket to the catalytic converter.
  2. Install the right (rear) catalytic converter (2). NOTE: Refer to «Fastener Notice»(/chevrolet/malibu/vi-2006-2008/remont/oem-general-information/#warnings-and-cautions__fastener-notice) .
  3. Install the right (rear) catalytic converter bolt (5) and nuts (1) at the exhaust manifold. Tighten: Tighten the nuts to 31 N.m (23 lb ft).
  4. Install the left (front) catalytic converter to right (rear) catalytic converter nuts (3). Tighten: Tighten the nuts to 31 N.m (23 lb ft). IMPORTANT: A special anti-seize compound is used on the HO2S threads. The compound consists of graphite suspended in fluid and glass beads. The graphite will burn away, but the glass beads will remain, making the sensor easier to remove. New or service sensors will already have the compound applied to the threads. If a sensor is removed from an engine and is to be reinstalled, the threads must have anti-seize compound applied before the reinstallation.
  5. If reinstalling the old HO2S, coat the threads with anti-seize compound GM P/N 12377953 or equivalent.
  6. Install the HO2S (2) using the J 39194-B . See «Special Tools»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system__special-tools) . Tighten: Tighten the sensor to 42 N.m (31 lb ft).
  7. Connect the lower right HO2S electrical connector (2).
  8. Install the CPA retainer (1).
  9. Ensure that the HO2S connector clip (3) is attached to the stud on the engine.
  10. Install the rear stabilizer shaft. Refer to «Stabilizer Shaft Replacement (Base Sedan)»(/chevrolet/malibu/vi-2006-2008/remont/suspension-rear/#rear-suspension-system) or «Stabilizer Shaft Replacement (Extended Sedan)»(/chevrolet/malibu/vi-2006-2008/remont/suspension-rear/#rear-suspension-system) .
  11. Install the muffler assembly. Refer to «Muffler Replacement (Sedan LS, LT, Maxx LT)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) or «Muffler Replacement (Sedan LTZ, Maxx LTZ)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) or «Muffler Replacement (Sedan SS, Maxx SS)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) .
  12. Perform the engine mount position adjustment procedure. Refer to «Engine Mount Position Adjustment»(/chevrolet/malibu/vi-2006-2008/remont/mechanical/#engine-mechanical-22l-l61__engine-mount-position-adjustment) .
  13. Start the engine, and check for exhaust leaks.
  1. Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vi-2006-2008/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) .
  2. If equipped with a 2.2L engine, remove the intermediate pipe to muffler nuts.
  3. If equipped with a 3.5L engine, remove the rear catalytic converter to muffler nuts.
  4. With the aid of an assistant, separate the muffler insulators (1) from the hangers.
  5. Remove the muffler assembly.

Scheme 8

Scheme 8: Installation Procedure
Scheme 8: Installation Procedure
  1. Install the muffler assembly.
  2. With the aid of an assistant, install the muffler insulators (1) to the hangers. NOTE: Refer to «Fastener Notice»(/chevrolet/malibu/vi-2006-2008/remont/oem-general-information/#warnings-and-cautions__fastener-notice) .
  3. If equipped with a 3.5L engine, install the rear catalytic converter to muffler nuts. Tighten: Tighten the nuts to 30 N.m (22 lb ft).
  4. If equipped with a 2.2L engine, install the intermediate pipe to muffler nuts. Tighten: Tighten the nuts to 30 N.m (22 lb ft).
  5. Lower the vehicle.
  1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vi-2006-2008/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) .
  2. Remove the rear catalytic converter to muffler nuts.
  3. With the aid of an assistant, separate the muffler insulators (1) from the hangers.
  4. Remove the muffler assembly.

Scheme 9

Scheme 9: Installation Procedure
Scheme 9: Installation Procedure
  1. Install the muffler assembly.
  2. With the aid of an assistant, install the muffler insulators (1) to the hangers. NOTE: Refer to «Fastener Notice»(/chevrolet/malibu/vi-2006-2008/remont/oem-general-information/#warnings-and-cautions__fastener-notice) .
  3. Install the rear catalytic converter to muffler nuts. Tighten: Tighten the nuts to 30 N.m (22 lb ft).
  4. Lower the vehicle.
  1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vi-2006-2008/remont/hoistjack/#general-information__lifting-and-jacking-the-vehicle) .
  2. Remove the rear catalytic converter to muffler nuts.
  3. With the aid of an assistant, separate the muffler insulators (1) from the hangers.
  4. Remove the muffler assembly.
  1. Install the muffler assembly.
  2. With the aid of an assistant, install the muffler insulators (1) to the hangers. NOTE: Refer to «Fastener Notice»(/chevrolet/malibu/vi-2006-2008/remont/oem-general-information/#warnings-and-cautions__fastener-notice) .
  3. Install the rear catalytic converter to muffler nuts. Tighten: Tighten the nuts to 30 N.m (22 lb ft).
  4. Lower the vehicle.
  1. If equipped with a 3.5L or 3.9L engine, remove the catalytic converters. Refer to «Catalytic Converter Replacement - Left Side (LZ4)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) or «Catalytic Converter Replacement - Left Side (LZ9)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) and «Catalytic Converter Replacement - Right Side (LZ4)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) or «Catalytic Converter Replacement - Right Side (LZ9)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) .
  2. If equipped with a 2.2L engine remove the exhaust manifold pipe. Refer to «Exhaust Manifold Pipe Replacement (L61)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) .
  3. Remove the heat shield nuts.
  4. Remove the heat shield.
  1. Position the heat shield to the underbody and the dash panel. NOTE: Refer to «Fastener Notice»(/chevrolet/malibu/vi-2006-2008/remont/oem-general-information/#warnings-and-cautions__fastener-notice) .
  2. Install the heat shield nuts. Tighten: Tighten the nuts to 10 N.m (89 lb in).
  3. If equipped with a 2.2L engine, install the exhaust manifold pipe. Refer to «Exhaust Manifold Pipe Replacement (L61)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) .
  4. If equipped with a 3.5L or 3.9L engine, install the catalytic converters. Refer to «Catalytic Converter Replacement - Left Side (LZ4)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) or «Catalytic Converter Replacement - Left Side (LZ9)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) and «Catalytic Converter Replacement - Right Side (LZ4)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) or «Catalytic Converter Replacement - Right Side (LZ9)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) .
  1. Remove the exhaust heat shield. Refer to «Exhaust Heat Shield Replacement»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) .
  2. Remove the muffler. Refer to «Muffler Replacement (Sedan LS, LT, Maxx LT)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) or «Muffler Replacement (Sedan LTZ, Maxx LTZ)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) or «Muffler Replacement (Sedan SS, Maxx SS)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) .
  3. Remove the exhaust pipe heat shield nuts.
  4. Remove the exhaust pipe heat shield.
  1. Position the exhaust pipe heat shield to the underbody. NOTE: Refer to «Fastener Notice»(/chevrolet/malibu/vi-2006-2008/remont/oem-general-information/#warnings-and-cautions__fastener-notice) .
  2. Install the exhaust pipe heat shield nuts. Tighten: Tighten the nuts to 10 N.m (89 lb in).
  3. Install the muffler. Refer to «Muffler Replacement (Sedan LS, LT, Maxx LT)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) or «Muffler Replacement (Sedan LTZ, Maxx LTZ)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) or «Muffler Replacement (Sedan SS, Maxx SS)»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) .
  4. Install the exhaust heat shield. Refer to «Exhaust Heat Shield Replacement»(/chevrolet/malibu/vi-2006-2008/remont/exhaust/#engine-exhaust-system) .

Exhaust System Description

IMPORTANTUse of non-OEM parts may cause driveability concerns.

The exhaust system carries exhaust gases, treated by the catalytic converter, through a resonator, if applicable and into the exhaust muffler where exhaust noise is lessened.

In order to secure the exhaust pipe to the exhaust manifold, a flange and seal-joint coupling is utilized. The exhaust system may utilize a slip-joint coupling design with a clamp and a U-bolt or a flange connection with a gasket.

Exhaust hangers and rubber insulators help to support the weight of the exhaust pipe along with insulating any exhaust system vibration, rattle, or noise.

Exhaust hangers also space the exhaust system away from the underbody of the vehicle and allows the exhaust system to expand as the exhaust system warms up.

Exhaust heat shields are used to protect the body and other components from damage due to the heat from the exhaust system.

The exhaust system may be comprised of the following components

  1. Exhaust manifold
  2. Exhaust pipes
  3. Catalytic converters
  4. Exhaust muffler
  5. Exhaust resonator, if equipped
  6. Exhaust tail pipe, if equipped
  7. Exhaust hangers
  8. Exhaust heat shields

Resonator

Some exhaust systems are equipped with a resonator. The resonator, located either before or after the muffler, allows the use of mufflers with less back pressure. Resonators are used when vehicle characteristics require specific exhaust tuning.

Catalytic Converter

The catalytic converter is an emission control device added to the engine exhaust system in order to reduce hydrocarbons (HC), carbon monoxide (CO), and oxides of nitrogen (NOx) pollutants from the exhaust gas.

The catalytic converter is comprised of a ceramic monolith substrate, supported in insulation and housed within a sheet metal shell. The substrate may be washcoated with 3 noble metals

  1. Platium (Pt)
  2. Palladium (Pd)
  3. Rhodium (Rh)

The catalyst in the converter is not serviceable.

Muffler

The exhaust muffler reduces the noise levels of the engine exhaust by the use of tuning tubes. The tuning tubes create channels inside the exhaust muffler that lower the sound levels created by the combustion of the engine.

Special Tools

Special Tools Illustration Tool Number/ Description J 35314-A Exhaust Back Pressure Gage J 39194-B Heated Oxygen Sensor Wrench

Scheme 10

Scheme 10: Special Tools
Scheme 10: Special Tools

Scheme 11

Scheme 11
Scheme 11