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Engine Exhaust System Chevrolet Malibu VII

Exhaust 5 illustrations ~5225 words

Specifications

Note. References to MH8 = A/T 6-Speed.

Fastener Tightening Specifications

ApplicationSpecification
MetricEnglish
Catalytic Converter to Exhaust Manifold Nut (LZ4/LY7)45 N.m33 lb ft
Catalytic Converter-Front to Catalytic Converter-Rear (LZ4/LY7)25 N.m18 lb ft
Catalytic Converter-Rear to Exhaust Flexible Pipe (LY7)25 N.m18 lb ft
Exhaust Flexible Pipe to Muffler Nut (LZ4/LY7)25 N.m18 lb ft
Exhaust Manifold Bolt (LZ4/LY7)20 N.m15 lb ft
Exhaust Manifold Nut (LAT)14 N.m10 lb ft
Exhaust Manifold Brace Bolt (LAT)58 N.m43 lb ft
Exhaust Manifold/Catalytic Converter to Exhaust Flexible Pipe Nut (LAT)30 N.m20 lb ft
Exhaust Manifold Heat Shield Bolt (LAT)23 N.m17 lb ft
Exhaust Manifold Heat Shield Bolt (LZ4/LY7)10 N.m89 lb in
Exhaust Manifold Lower Heat Shield Bolt (LY7)10 N.m89 lb in
Exhaust Manifold Lower Heat Shield Bolt (LY7)50 N.m37 lb ft
Exhaust Manifold Pipe to Muffler Nut (LAT)25 N.m18 lb ft
Exhaust Pipe Heat Shield Nut10 N.m89 lb in
Frame Bolt - First Pass100 N.m74 lb ft
Frame Bolt - Final Pass90 Degrees
Heat Shield Nut10 N.m89 lb in

Adhesives, Fluids, Lubricants, and Sealers

ApplicationType of MaterialGM Part NumberBrazil
United StatesCanada
Exhaust Manifold and Oxygen Sensor ThreadsAnti-Seize12377953Refer to Owner's Manual.

Symptoms - Engine Exhaust

  1. Review the exhaust system description in order to familiarize yourself with the exhaust system components and the intended function of the components. Refer to «Exhaust System Description»(/chevrolet/malibu/vii-2008-2012/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/vii-2008-2012/remont/oem-general-information/#vehicle-diagnostic-information-diagnostic-information-and-procedures__strategy-based-diagnosis) .

Visual/Physical Inspection

  1. Inspect for aftermarket or non-OEM devices such as, but not limited to; tailpipe extensions, headers, and exhaust cutouts. Any aftermarket exhaust system devices 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/vii-2008-2012/remont/exhaust/#engine-exhaust-system)
  2. Poor acceleration Refer to «Restricted Exhaust»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system)
  3. Poor fuel economy Refer to «Restricted Exhaust»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system)
  4. Excessive smoke diesel Refer to «Restricted Exhaust»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system)
  5. Exhaust hissing noise Refer to «Exhaust Leakage»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system__exhaust-leakage)
  6. Exhaust popping noise Refer to «Exhaust Leakage»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system__exhaust-leakage)
  7. Exhaust rattle noise Refer to «Exhaust Noise»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system__exhaust-noise)
  8. Loud exhaust noise Refer to «Exhaust Noise»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system__exhaust-noise)
  9. Exhaust buzz, groan, hum noise Refer to «Exhaust Noise»(/chevrolet/malibu/vii-2008-2012/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 Gauge. See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) . 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
1NOTE: This procedure is not used in Brazil. Did 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
3WARNING: Refer to Hot Exhaust System Warning . Remove the pre-catalyst HO2S. Refer to one of the following: Heated Oxygen Sensor Replacement - Sensor 1 (LAT and LE5) Heated Oxygen Sensor Replacement - Sensor 1 (LE8 w/MH8) for the 2.4L 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 3.6L engine Install the J 35314-A Exhaust Back Pressure Gauge 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 gauge. 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 Replacement - Sensor 1 (LAT and LE5) Heated Oxygen Sensor Replacement - Sensor 1 (LE8 w/MH8) for the 2.4L 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 3.6L engine Remove the post-catalyst HO2S. Refer to one of the following: Heated Oxygen Sensor Replacement - Sensor 2 (LAT and LE5) Heated Oxygen Sensor Replacement - Sensor 2 (LE5 w/MH5) for the 2.4L 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 3.6L 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 gauge. 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 (LY7) and/or Catalytic Converter Replacement - Right Side (LZ4) or Catalytic Converter Replacement - Right Side (LY7) . 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 Replacement - Sensor 2 (LAT and LE5) Heated Oxygen Sensor Replacement - Sensor 2 (LE5 w/MH5) for the 2.4L 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 3.6L engine Clear any codes. Road test the vehicle in order to verify the repair. Did you correct the condition?System OKGo to Step 2
NOTE
This procedure is not used in Brazil.
WARNING
Refer to Hot Exhaust System Warning .

Exhaust Leakage

ProblemAction
WARNING: 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 (LE5 or LE9) or Exhaust Manifold Replacement (LE5 or LE9 With MH8) or Exhaust Manifold Replacement - Left Side (LY7) or Exhaust Manifold Replacement - Left Side (LZ4) or Exhaust Manifold Replacement - Right Side (LY7) or Exhaust Manifold Replacement - Right Side (LZ4) .
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 Exhaust Muffler Replacement (LZ4) or Exhaust Muffler Replacement (LE5 or LE9 With MH8) or Exhaust Muffler Replacement (LY7) .
WARNING
While engine is operating, the exhaust system will become extremely hot. To prevent burns avoid contacting a hot exhaust system.

Exhaust Noise

ConditionAction
WARNING: Refer to Hot Exhaust System Warning . NOTE: This procedure is not used in Brazil. 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 Exhaust Muffler Replacement (LZ4) or Exhaust Muffler Replacement (LE5 or LE9 With MH8) or Exhaust Muffler Replacement (LY7) .
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: Exhaust Manifold Replacement (LE5 or LE9) Exhaust Manifold Replacement (LE5 or LE9 With MH8) Catalytic Converter Replacement - Left Side (LZ4) Catalytic Converter Replacement - Left Side (LY7) Catalytic Converter Replacement - Right Side (LZ4) Catalytic Converter Replacement - Right Side (LY7) Exhaust Muffler Replacement (LZ4) Exhaust Muffler Replacement (LE5 or LE9 With MH8) Exhaust Muffler Replacement (LY7)
WARNING
Refer to Hot Exhaust System Warning .
NOTE
This procedure is not used in Brazil.

Removal Procedure

  1. Remove the exhaust manifold heat shield. Refer to «Exhaust Manifold Heat Shield Replacement (LE5 or LE9 With MH8)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) .
  2. Remove the heated oxygen sensor (HO2S). Refer to «Heated Oxygen Sensor Replacement - Sensor 1 (LAT and LE5)»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-24l-repair-instructions) or «Heated Oxygen Sensor Replacement - Sensor 1 (LE9 w/MH8)»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-24l-repair-instructions) .
  3. If equipped with a LE5, remove the exhaust manifold pipe. Refer to «Exhaust Manifold Pipe Replacement (LE5 or LE9)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) .
  4. If equipped with a LAT, remove the catalytic converter. Refer to «Catalytic Converter Replacement (LAT or LE5)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) or «Catalytic Converter Replacement (LE5 or LE9 With MH8)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) .
  5. Lower the vehicle.
  6. Remove the upper exhaust manifold brace bolt (1).
  7. Remove and discard the exhaust manifold nuts (1).
  8. Remove the exhaust manifold/catalytic converter assembly (2).
  9. Remove and discard the exhaust manifold gasket.

Installation Procedure

  1. Install a NEW exhaust manifold gasket onto the manifold studs.
  2. Install the exhaust manifold/catalytic converter assembly (2).
  3. Install the NEW exhaust manifold nuts (1) finger tight.
  4. Install the upper exhaust manifold brace bolt (1) and tighten to 58 N.m (43 lb ft).
  5. Tighten the exhaust manifold nuts in the sequence shown to 14 N.m (10 lb ft).
  6. Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vii-2008-2012/remont/ignition-switchsteering-lock/#general-information) .
  7. If equipped with a LE5, install the exhaust manifold pipe. Refer to «Exhaust Manifold Pipe Replacement (LE5 or LE9)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system)
  8. If equipped with a LAT, install the catalytic converter. Refer to «Catalytic Converter Replacement (LE5 or LE9 With MH8)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) .
  9. Install the HO2S. Refer to «Heated Oxygen Sensor Replacement - Sensor 1 (LAT and LE5)»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-24l-repair-instructions) or «Heated Oxygen Sensor Replacement - Sensor 1 (LE9 w/MH8)»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-24l-repair-instructions) .
  10. Install the exhaust manifold heat shield. Refer to «Exhaust Manifold Heat Shield Replacement (LE5 or LE9 With MH8)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) .

Scheme 1

Scheme 1: Exhaust Manifold Replacement (LE5 or LE9 With MH8)
Scheme 1: Exhaust Manifold Replacement (LE5 or LE9 With MH8)
CalloutComponent Name
Preliminary procedures Remove the exhaust manifold heat shield. Refer to Exhaust Manifold Heat Shield Replacement (LE5 or LE9 With MH8) Remove the exhaust extension pipe. Refer to Exhaust Pipe Replacement (LE5 or LE9 With MH8)
1Nut (Qty 10) CAUTION: Refer to Fastener Caution . Tighten: 14 N.m (124 lb in)
2Exhaust Manifold Procedure Remove and discard the Exhaust manifold gasket. Clean any exhaust manifold gasket debris from the cylinder head and exhaust manifold. Tighten the Manifold nuts working from the center out.
CAUTION
Refer to Fastener Caution .
  1. Remove the exhaust manifold heat shield. Refer to «Exhaust Manifold Heat Shield Replacement - Left Side (LY7)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) .
  2. Remove the oil level indicator. Refer to «Oil Level Indicator Tube Replacement»(/chevrolet/malibu/vii-2008-2012/remont/mechanical/#engine-mechanical-36l-repair-instructions-on-vehicle-1-of-2) .
  3. Remove the catalytic converter to exhaust manifold nuts (1).
  4. Remove the exhaust manifold bolts (1).
  5. Remove the exhaust manifold and gasket. Discard the gasket.
  1. Install one exhaust manifold bolt to the exhaust manifold.
  2. Install the NEW exhaust manifold gasket onto the cylinder head and bolt.
  3. Install the exhaust manifold (with gasket) to the catalytic converter and the cylinder head.
  4. Install the remaining exhaust manifold bolts (1) and tighten to 25 N.m (18 lb ft).
  5. Install the catalytic converter to exhaust manifold nuts (1) and tighten to 45 N.m (33 lb ft).
  6. Install the oil level indicator. Refer to «Oil Level Indicator Tube Replacement»(/chevrolet/malibu/vii-2008-2012/remont/mechanical/#engine-mechanical-36l-repair-instructions-on-vehicle-1-of-2) .
  7. Install the exhaust manifold heat shield. Refer to «Exhaust Manifold Heat Shield Replacement - Left Side (LY7)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) .
  8. Inspect for exhaust leaks.

Special Tools

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

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

Note. The 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).

Note. The 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/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-35l-repair-instructions) .
  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/vii-2008-2012/remont/exhaust/#engine-exhaust-system) .
  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/vii-2008-2012/remont/ignition-switchsteering-lock/#general-information) .
  9. Remove the left catalytic converter. Refer to «Catalytic Converter Replacement - Left Side (LZ4)»(/chevrolet/malibu/vii-2008-2012/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.
  1. Install a NEW exhaust manifold gasket onto the cylinder head studs.
  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 left catalytic converter. Refer to «Catalytic Converter Replacement - Left Side (LZ4)»(/chevrolet/malibu/vii-2008-2012/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).
  7. Coat the threads of the HO2S with anti-seize compound. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system__adhesives-fluids-lubricants-and-sealers)
  8. Install the HO2S using J 39194-B . See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) . 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/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-35l-repair-instructions) .
  1. Remove the catalytic converter. Refer to «Catalytic Converter Replacement - Right Side (LY7)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) .
  2. Remove the exhaust manifold lower bolts.
  3. Lower the vehicle half way.
  4. Remove the exhaust manifold upper bolts.
  5. Remove the exhaust manifold.
  6. Remove and discard the exhaust manifold gasket.
  1. Install one upper exhaust manifold bolt (1) to the exhaust manifold.
  2. Place the NEW exhaust manifold gasket onto the bolt.
  3. Position and install the exhaust manifold (with gasket) to the cylinder head.
  4. Loosely install the remaining upper exhaust manifold bolts.
  5. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vii-2008-2012/remont/ignition-switchsteering-lock/#general-information) .
  6. Loosely install the lower exhaust manifold bolts.
  7. Tighten the exhaust manifold bolts to 25 N.m (18 lb ft).
  8. Install the catalytic converter. Refer to «Catalytic Converter Replacement - Right Side (LY7)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) .

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

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

Note. The 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).

Note. The 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 (LZ4)»(/chevrolet/malibu/vii-2008-2012/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/vii-2008-2012/remont/exhaust/#engine-exhaust-system) .
  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/vii-2008-2012/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.
  1. Install a NEW exhaust manifold gasket onto the cylinder head studs.
  2. Install the exhaust manifold.
  3. Install the exhaust manifold bolts and tighten to 20 N.m (15 lb ft).
  4. Install the right catalytic converter. Refer to «Catalytic Converter Replacement - Right Side (LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) .
  5. Install the exhaust manifold heat shield and bolts. Tighten the bolts to 10 N.m (89 lb in).
  6. Coat the threads of the HO2S with anti-seize compound. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system__adhesives-fluids-lubricants-and-sealers)
  7. Install the HO2S using J 39194-B . See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) . 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 (LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
  1. Remove the heated oxygen sensor (HO2S). Refer to «Heated Oxygen Sensor Replacement - Sensor 2 (LAT and LE5)»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-24l-repair-instructions) or «Heated Oxygen Sensor Replacement - Sensor 2 (MH8)»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-24l-repair-instructions) .
  2. Remove the exhaust manifold pipe to muffler nuts.
  3. Remove the exhaust manifold/catalytic converter to exhaust manifold pipe nuts.
  4. Remove the first muffler hanger insulator.
  5. Gently pull back and separate the muffler from the exhaust manifold pipe studs.
  6. 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.
  4. Install the exhaust manifold/catalytic converter to exhaust manifold pipe nuts and tighten to 30 N.m (20 lb ft).
  5. Install the exhaust manifold pipe to muffler nuts and tighten to 25 N.m (18 lb ft).
  6. Install the HO2S. Refer to «Heated Oxygen Sensor Replacement - Sensor 2 (LAT and LE5)»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-24l-repair-instructions) or «Heated Oxygen Sensor Replacement - Sensor 2 (MH8)»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-24l-repair-instructions) .
  1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vii-2008-2012/remont/ignition-switchsteering-lock/#general-information) .
  2. Remove the exhaust pipe (2) to converter nuts (1).
  3. Remove the exhaust pipe to muffler assembly nuts (2).
  4. Move the muffler assembly rearward in order to disengage the exhaust pipe.
  5. Discard both gaskets.
  1. Install new gaskets to the exhaust pipe and muffler assembly.
  2. Move the muffler assembly rearward in order to install the exhaust between the converter and muffler assembly.
  3. Install the exhaust pipe to muffler assembly nuts (1) and tighten to 25 N.m (18 lb ft).
  4. Install exhaust pipe (2) to converter nuts (1) and tighten to 25 N.m (18 lb ft).
  5. Lower the vehicle.
  1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vii-2008-2012/remont/ignition-switchsteering-lock/#general-information) .
  2. Remove the exhaust pipe to muffler nuts.
  3. Remove the exhaust pipe to right catalytic converter nuts.
  4. Pull back the muffler assembly in order to remove the exhaust pipe from the right catalytic converter.
  5. Remove and discard the exhaust pipe gasket.
  1. Install a NEW exhaust pipe gasket.
  2. Pull back the muffler assembly in order to install the exhaust pipe to the right catalytic converter.
  3. Install the exhaust pipe to right catalytic converter nuts and tighten to 25 N.m (18 lb ft).
  4. Install the exhaust pipe to muffler nuts and tighten to 25 N.m (18 lb ft).
  5. Lower the vehicle.
  1. Remove the heated oxygen sensor. Refer to «Heated Oxygen Sensor Replacement - Sensor 2 (LAT and LE5)»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-24l-repair-instructions) or «Heated Oxygen Sensor Replacement - Sensor 2 (MH8)»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-24l-repair-instructions) .
  2. Remove the catalytic converter to exhaust manifold nuts (1).
  3. Remove the catalytic converter to muffler nuts (1).
  4. Separate the exhaust pipe from the catalytic converter studs.
  5. Position and support the exhaust pipe out of the way.
  6. Remove the catalytic converter (2) and gasket.
  1. Install the catalytic converter (2) along with a NEW gasket to the exhaust manifold.
  2. Position and join the exhaust pipe to the catalytic converter studs.
  3. Install the catalytic converter to muffler nuts and tighten to 25 N.m (18 lb ft).
  4. Install the catalytic converter to exhaust manifold nuts (1) and tighten to 45 N.m (33 lb ft).
  5. Install the heated oxygen sensor. Refer to «Heated Oxygen Sensor Replacement - Sensor 2 (LAT and LE5)»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-24l-repair-instructions) or «Heated Oxygen Sensor Replacement - Sensor 2 (MH8)»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-24l-repair-instructions) .
WARNINGRefer to Hot Exhaust System Warning
  1. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vii-2008-2012/remont/ignition-switchsteering-lock/#general-information)
  2. Remove the heated oxygen sensor. Refer to «Heated Oxygen Sensor Replacement - Sensor 2 (LAT and LE5)»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-24l-repair-instructions) or «Heated Oxygen Sensor Replacement - Sensor 2 (MH8)»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-24l-repair-instructions) .
  3. Remove the catalytic converter to muffler nuts (1).
  4. Separate the exhaust flexible pipe (2) from the catalytic converter studs.
  5. Position and support the exhaust pipe (2) out of the way.
  6. Remove the converter to bracket bolt (1).
  7. Remove the catalytic converter to exhaust manifold nuts (3).
  8. Remove the catalytic converter (2) and gasket. Discard the Catalytic converter gaskets.
  1. Install a NEW gasket to the catalytic converter.
  2. Position the catalytic converter (2) to the exhaust manifold and converter bracket.
  3. Loosely install the converter to manifold nuts (3) and converter bracket bolt (1).
  4. Tighten the converter to manifold nuts to 45 N.m (33 lb ft).
  5. Tighten the converter to bracket bolt to 58 N.m (42 lb ft).
  6. Install a NEW gasket between the converter and exhaust pipe (2).
  7. Connect the exhaust flexible pipe to the converter and tighten the nuts (1) to 25 N.m (18 lb ft).
  8. Install the heated oxygen sensor. Refer to «Heated Oxygen Sensor Replacement - Sensor 2 (LAT and LE5)»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-24l-repair-instructions) or «Heated Oxygen Sensor Replacement - Sensor 2 (MH8)»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-24l-repair-instructions) .
  9. Lower the vehicle

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

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

Note. The 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.

Note. The 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/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-35l-repair-instructions) .
  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 «Exhaust Muffler Replacement (LZ4)»(/chevrolet/malibu/vii-2008-2012/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 (1, 2) using the J 39194-B . See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) .
  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.
  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).
  5. Install the right (rear) catalytic converter bolt (5) and nuts (1) at the exhaust manifold and tighten to 45 N.m (33 lb ft).
  6. Install the left (front) catalytic converter to right (rear) catalytic converter nuts (3) and tighten to 25 N.m (18 lb ft).
  7. If reinstalling the old HO2S, coat the threads with anti-seize compound. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system__adhesives-fluids-lubricants-and-sealers)
  8. Install the lower right and left HO2S (1, 2) using the J 39194-B . See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) . 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 «Exhaust Muffler Replacement (LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) .
  14. Install the left (front) catalytic converter nuts (1) at the exhaust manifold and tighten to 45 N.m (33 lb ft).
  15. Remove the exhaust manifold heat shield bolts and shield. 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/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-35l-repair-instructions) .
  1. Remove the exhaust manifold heat shield. Refer to «Exhaust Manifold Heat Shield Replacement - Left Side (LY7)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) .
  2. Remove the left catalytic converter to exhaust manifold nuts (1).
  3. Raise and support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vii-2008-2012/remont/ignition-switchsteering-lock/#general-information) .
  4. Disconnect the bank 2 sensor 2 heated oxygen sensor (HO2S) electrical connector (3) from the engine wiring harness electrical connector (3).
  5. Remove the left catalytic converter (3) to right catalytic converter (1) nuts (2).
  6. Remove the left catalytic converter from the vehicle.
  7. Discard the catalytic converter to exhaust manifold gasket (2).
  8. Discard the left catalytic converter to right catalytic converter gasket (1).
  1. Install a NEW catalytic converter seal (2) onto the catalytic converter.
  2. Install the catalytic converter to the vehicle.
  3. Install a NEW left catalytic converter to right catalytic converter gasket (1).
  4. Install the left catalytic converter to right catalytic converter nuts (2) and tighten to 22 N.m (16 lb ft).
  5. Connect the bank 2 sensor 2 HO2S electrical connector (3) to the engine wiring harness electrical connector (2).
  6. Install the left catalytic converter to exhaust manifold nuts (1) and tighten to 45 N.m (33 lb ft).
  7. Install the exhaust manifold heat shield. Refer to «Exhaust Manifold Heat Shield Replacement - Left Side (LY7)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) .
  8. Lower the vehicle and inspect for exhaust leaks.

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

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

Note. The 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.

Note. The HO2S may be difficult to remove when the engine temperature is less than 48°C (120°F).

  1. Remove the muffler assembly. Refer to «Exhaust Muffler Replacement (LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) .
  2. Remove the rear stabilizer shaft. Refer to «Stabilizer Shaft Replacement»(/chevrolet/malibu/vii-2008-2012/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/vii-2008-2012/remont/exhaust/#engine-exhaust-system) .
  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).
  3. Install the right (rear) catalytic converter bolt (5) and nuts (1) at the exhaust manifold and tighten to 45 N.m (33 lb ft).
  4. Install the left (front) catalytic converter to right (rear) catalytic converter nuts (3) and tighten to 25 N.m (18 lb ft).
  5. If reinstalling the old HO2S, coat the threads with anti-seize compound. Refer to «Adhesives, Fluids, Lubricants, and Sealers»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system__adhesives-fluids-lubricants-and-sealers)
  6. Install the lower right HO2S (2) using the J 39194-B . See «Special Tools»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) . 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»(/chevrolet/malibu/vii-2008-2012/remont/suspension-rear/#rear-suspension-system) .
  10. Install the muffler assembly. Refer to «Exhaust Muffler Replacement (LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) .
  1. Remove the exhaust manifold heat shield. Refer to «Exhaust Manifold Heat Shield Replacement - Right Side (LY7)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) .
  2. Remove the catalytic converter to exhaust manifold nuts (1).
  3. Remove the bank 1 sensor 2 heated oxygen sensor (HO2S). Refer to «Heated Oxygen Sensor Replacement - Bank 1 Sensor 2»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-36l-repair-instructions) .
  4. Remove the left catalytic converter (3) to right catalytic converter (1) nuts (2).
  5. Remove the exhaust pipe to right catalytic converter nuts.
  6. Remove the catalytic converter from the vehicle.
  7. Remove and discard the catalytic converter to exhaust manifold gasket (1).
  8. Remove and discard the left catalytic converter to right catalytic converter gasket (2).
  1. Install a NEW catalytic converter to exhaust manifold gasket (1) onto the catalytic converter.
  2. Install the catalytic converter to the vehicle.
  3. Install a NEW left catalytic converter to right catalytic converter gasket (2) between the converters.
  4. Install the left catalytic converter (3) to right catalytic converter (1) nuts (2) and tighten to 22 N.m (16 lb ft).
  5. Install the exhaust pipe to right catalytic converter nuts and tighten to 25 N.m (18 lb ft).
  6. Install the bank 1 sensor 2 HO2S. Refer to «Heated Oxygen Sensor Replacement - Bank 1 Sensor 2»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-36l-repair-instructions) .
  7. Install the catalytic converter to exhaust manifold nuts (1) and tighten to 45 N.m (33 lb ft).
  8. Install the exhaust manifold heat shield. Refer to «Exhaust Manifold Heat Shield Replacement - Right Side (LY7)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) .
  1. Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vii-2008-2012/remont/ignition-switchsteering-lock/#general-information) .
  2. If equipped with a 2.4L 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, remove the muffler insulators from the hangers.
  5. Remove the muffler assembly.
  1. With the aid of an assistant, position the muffler assembly.
  2. Install the muffler insulators to the hangers.
  3. If equipped with a 3.5L engine, install the exhaust pipe to muffler nuts and tighten to 25 N.m (18 lb ft).
  4. If equipped with a 2.4L engine, install the exhaust manifold pipe to muffler nuts and tighten to 30 N.m (22 lb ft).

Scheme 2

Scheme 2: Exhaust Muffler Replacement (LE5 or LE9 With MH8)
Scheme 2: Exhaust Muffler Replacement (LE5 or LE9 With MH8)
CalloutComponent Name
Preliminary Procedure: Raise and Support the vehicle. Refer to Lifting and Jacking the Vehicle .
1Nut (Qty 2) CAUTION: Refer to Fastener Caution . Tighten: 25 N.m (18 lb ft)
2Hanger (Qty 2) Procedure: Remove the hangers from muffler assembly only.
3Hanger (Qty 3) Procedure: Remove the hangers from muffler assembly only.
4Muffler Assembly Procedure: Remove the muffler assembly rearward over the rear axle.
CAUTION
Refer to Fastener Caution .
  1. Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vii-2008-2012/remont/ignition-switchsteering-lock/#general-information) .
  2. Remove the exhaust pipe to muffler nuts.
  3. With the aid of an assistant, remove the muffler insulators from the hangers.
  4. Remove the muffler assembly.
  5. Replace exhaust gasket.
  1. With the aid of an assistant, position the muffler assembly.
  2. Install the muffler insulators to the hangers.
  3. Install the exhaust pipe to muffler nuts and tighten to 25 N.m (18 lb ft).
  4. Lower the vehicle.

J-45059: Angle Meter

  1. If equipped with a 2.4L engine remove the exhaust manifold pipe. Refer to «Catalytic Converter Replacement (LAT or LE5)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) or «Catalytic Converter Replacement (LE5 or LE9 With MH8)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) or «Exhaust Pipe Replacement (LE5 or LE9 With MH8)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) or «Exhaust Pipe Replacement (LY7)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) .
  2. If equipped with a 3.5L or 3.6L engine, remove the catalytic converters. Refer to «Catalytic Converter Replacement - Left Side (LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) or «Catalytic Converter Replacement - Left Side (LY7)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) and «Catalytic Converter Replacement - Right Side (LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) or «Catalytic Converter Replacement - Right Side (LY7)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) .
  3. Separate the first two muffler insulators from the hangers and support the muffler pipe.
  4. Remove the left frame bolts (4).
  5. Remove the left frame reinforcement (3).
  6. Remove the heat shield nuts.
  7. Remove the heat shield.
  1. Position the heat shield to the underbody and the dash panel.
  2. Install the heat shield nuts and tighten to 10 N.m (89 lb in).
  3. Install the left frame reinforcement (3).
  4. Install the left frame bolts (4). Tighten the bolts to 100 N.m (74 lb ft) plus an additional 90 degrees using the J-45059: meter.
  5. Raise the muffler pipe into position and install the first two muffler insulators onto the hangers.
  6. If equipped with a 3.5L or 3.6L engine, install the catalytic converters. Refer to «Catalytic Converter Replacement - Left Side (LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) or «Catalytic Converter Replacement - Left Side (LY7)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) and «Catalytic Converter Replacement - Right Side (LZ4)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) or «Catalytic Converter Replacement - Right Side (LY7)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) .
  7. If equipped with a 2.4L engine, install the exhaust manifold pipe. Refer to «Catalytic Converter Replacement (LAT or LE5)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) or «Catalytic Converter Replacement (LE5 or LE9 With MH8)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) .
  1. Remove the catalytic converter. Refer to «Catalytic Converter Replacement - Right Side (LY7)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) .
  2. Remove the exhaust manifold lower heat shield bolts (1, 2).
  3. Remove the exhaust manifold lower heat shield.
  1. Position the exhaust manifold lower heat shield to the engine.
  2. Install the exhaust manifold lower heat shield bolts (1, 2). Tighten the bolt (1) to 10 N.m (89 lb in). Tighten the bolt (2) to 50 N.m (37 lb ft).
  3. Install the catalytic converter. Refer to «Catalytic Converter Replacement - Right Side (LY7)»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) .

Scheme 3

Scheme 3: Exhaust Manifold Heat Shield Replacement (LE5 or LE9 With MH8)
Scheme 3: Exhaust Manifold Heat Shield Replacement (LE5 or LE9 With MH8)
CalloutComponent Name
Preliminary procedures: Remove the air cleaner outlet duct. Refer to Air Cleaner Outlet Duct Replacement
1Bolt (Qty 3) CAUTION: Refer to Fastener Caution . Tighten: 10 N.m (89 lb in)
2Exhaust Manifold Heat Shield
CAUTION
Refer to Fastener Caution .
  1. Remove the air cleaner outlet duct. Refer to «Air Cleaner Outlet Duct Replacement»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-24l-repair-instructions) .
  2. Disconnect the engine wiring harness electrical connector (1) from the heater coolant pump (2).
  3. Remove the exhaust manifold heat shield bolt (3) securing the heater coolant pump bracket.
  4. Reposition and secure the heater coolant pump (1) and bracket out of the way.
  5. Remove the remaining exhaust manifold heat shield bolts (1).
  6. Remove the exhaust manifold heat shield (2).
  1. Install the exhaust manifold heat shield (2) onto the manifold.
  2. Install the 2 exhaust manifold heat shield bolts (1) and tighten to 23 N.m (17 lb ft).
  3. Position the heater coolant pump (1) and bracket to the heat shield bracket.
  4. Install the remaining exhaust manifold heat shield bolt (3) and tighten to 23 N.m (17 lb ft).
  5. Connect the engine wiring harness electrical connector (1) to the heater coolant pump (2).
  6. Install the air cleaner outlet duct. Refer to «Air Cleaner Outlet Duct Replacement»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-24l-repair-instructions) .
WARNINGRefer to Exhaust Service Warning .
  1. Remove the bank 1 sensor 1 heated oxygen sensor (HO2S). Refer to «Heated Oxygen Sensor Replacement - Bank 1 Sensor 1»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-35l-repair-instructions) .
  2. Remove the exhaust manifold heat shield bolts.
  3. Remove the exhaust manifold heat shield.
  1. Install the exhaust manifold heat shield.
  2. Install the exhaust manifold heat shield bolts and tighten to 10 N.m (89 lb in).
  3. Install the bank 1 sensor 1 HO2S. Refer to «Heated Oxygen Sensor Replacement - Bank 1 Sensor 1»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-35l-repair-instructions) .
  1. Remove the bank 1 sensor 1 heated oxygen sensor (HO2S). Refer to «Heated Oxygen Sensor Replacement - Bank 1 Sensor 1»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-36l-repair-instructions) .
  2. Raise the vehicle to an appropriate height to reach the heat shield bolts. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/malibu/vii-2008-2012/remont/ignition-switchsteering-lock/#general-information) .
  3. Remove the exhaust manifold heat shield bolts.
  4. Remove the exhaust manifold heat shield.
  1. Install and position the exhaust manifold heat shield onto the exhaust manifold.
  2. Install the exhaust manifold heat shield bolts and tighten to 10 N.m (89 lb in).
  3. Install the bank 1 sensor 1 HO2S. Refer to «Heated Oxygen Sensor Replacement - Bank 1 Sensor 1»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-36l-repair-instructions) .
  1. Remove the bank 2 sensor 1 heated oxygen sensor (HO2S). Refer to «Heated Oxygen Sensor Replacement - Bank 2 Sensor 1»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-36l-repair-instructions) .
  2. Remove the exhaust manifold heat shield bolts.
  3. Remove the exhaust manifold heat shield.
  1. Install the exhaust manifold heat shield.
  2. Install the exhaust manifold heat shield bolts and tighten to 10 N.m (89 lb in).
  3. Install the bank 2 sensor 1 HO2S. Refer to «Heated Oxygen Sensor Replacement - Bank 2 Sensor 1»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-36l-repair-instructions) .
WARNINGRefer to Exhaust Service Warning .
  1. Remove the bank 2 sensor 1 heated oxygen sensor (HO2S). Refer to «Heated Oxygen Sensor Replacement - Bank 2 Sensor 1»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-35l-repair-instructions) .
  2. Remove the exhaust manifold heat shield bolts.
  3. Remove the exhaust manifold heat shield.
  1. Install the exhaust manifold heat shield.
  2. Install the exhaust manifold heat shield bolts and tighten to 10 N.m (89 lb in).
  3. Install the bank 2 sensor 1 HO2S. Refer to «Heated Oxygen Sensor Replacement - Bank 2 Sensor 1»(/chevrolet/malibu/vii-2008-2012/remont/testing-diagnostics/#engine-controls-and-fuel-35l-repair-instructions) .
  1. Remove the exhaust heat shield. Refer to «Exhaust Heat Shield Replacement»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) .
  2. Remove the exhaust pipe heat shield nuts.
  3. Remove the exhaust pipe heat shield.
  1. Position the exhaust pipe heat shield to the underbody.
  2. Install the exhaust pipe heat shield nuts and tighten to 10 N.m (89 lb in).
  3. Install the exhaust heat shield. Refer to «Exhaust Heat Shield Replacement»(/chevrolet/malibu/vii-2008-2012/remont/exhaust/#engine-exhaust-system) .

Exhaust System Description

Note. Use 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. Platinum (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.

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

Scheme 4

Scheme 4: Special Tools
Scheme 4: Special Tools

Scheme 5

Scheme 5
Scheme 5