Engine Exhaust System Chevrolet Chevy Express H2500

Fastener Tightening Specifications

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/chevy-express-h2500/2003-2003/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.

Visual/Physical Inspection

1. Inspect for aftermarket or non-OEM devices such as, but not including; tailpipe extensions, headers, and exhaust cutouts. 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/chevy-express-h2500/2003-2003/remont/exhaust/#engine-exhaust-system__restricted-exhaust) .
2. Poor acceleration Refer to «Restricted Exhaust»(/chevrolet/chevy-express-h2500/2003-2003/remont/exhaust/#engine-exhaust-system__restricted-exhaust) .
3. Poor fuel economy Refer to «Restricted Exhaust»(/chevrolet/chevy-express-h2500/2003-2003/remont/exhaust/#engine-exhaust-system__restricted-exhaust) .
4. Excessive smoke (diesel) Refer to «Restricted Exhaust»(/chevrolet/chevy-express-h2500/2003-2003/remont/exhaust/#engine-exhaust-system__restricted-exhaust) .
5. Exhaust hissing noise Refer to «Exhaust Leakage»(/chevrolet/chevy-express-h2500/2003-2003/remont/exhaust/#engine-exhaust-system) .
6. Exhaust popping noise Refer to «Exhaust Leakage»(/chevrolet/chevy-express-h2500/2003-2003/remont/exhaust/#engine-exhaust-system) .
7. Exhaust rattle noise Refer to «Exhaust Noise»(/chevrolet/chevy-express-h2500/2003-2003/remont/exhaust/#engine-exhaust-system) .
8. Loud exhaust noise Refer to «Exhaust Noise»(/chevrolet/chevy-express-h2500/2003-2003/remont/exhaust/#engine-exhaust-system) .
9. Exhaust buzz, groan, hum noise Refer to «Exhaust Noise»(/chevrolet/chevy-express-h2500/2003-2003/remont/exhaust/#engine-exhaust-system) .

Restricted Exhaust

Diagnostic Aids

If the vehicle is equipped with a 6.5L diesel engine do not perform this diagnostic. The exhaust system does not have a location for installing the J 35314-A . Instead remove the suspect component, operate the vehicle, verify for improved performance. If performance is improved then replace the faulty component.

Test Description

Tools Required

J 35314-A Exhaust Back Pressure Gage

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

1. 4. 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 . Removing the AIR check valve or HO2S sensor may set a DTC. When finishing this diagnostic table, be sure to clear all codes.
2. 5. This step will isolate the catalytic converter from the remainder of the exhaust system.
3. 8. Confirming that the condition has been fixed is essential. If the symptom still exists and the vehicle has a dual exhaust system, proceed to step 2 and repeat diagnostic procedure on the opposite exhaust pipe.

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1. Remove the engine cover.
2. Disconnect the engine coolant temperature (ECT) gage sensor electrical connector.
3. Raise the vehicle.
4. Remove the left front tire.
5. Remove the left fender wheelhouse extension (1).
6. Remove the catalytic converter assembly. Refer to «Catalytic Converter Replacement (4.3L)»(/chevrolet/chevy-express-h2500/2003-2003/remont/exhaust/#engine-exhaust-system) or «Catalytic Converter Replacement (Dual Exhaust - Right)»(/chevrolet/chevy-express-h2500/2003-2003/remont/exhaust/#engine-exhaust-system) or «Catalytic Converter Replacement (Dual Exhaust - Left)»(/chevrolet/chevy-express-h2500/2003-2003/remont/exhaust/#engine-exhaust-system) .
7. Remove the EGR valve inlet pipe from the exhaust manifold.
8. Remove the spark plug wires from the spark plugs.
9. Remove the spark plug wire support bolts.
10. Remove the spark plug wire support with the spark plug wires.
11. Remove the spark plugs.
12. Remove the exhaust manifold, gaskets and the spark plug wire shields from underneath the vehicle.
13. Clean all gasket surfaces.

Installation Procedure

Important: To assist in installing the exhaust manifold to the engine, the tabs on a NEW exhaust manifold gasket will hold the gasket and the bolts in place.

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1. Sub-assemble the NEW gaskets, the spark plug wire shields, and the bolts to the exhaust manifold.
2. Ensure that the exhaust manifold bolts are held in place by the tabs on the exhaust manifold gaskets. CAUTION: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.
3. Install the exhaust manifold. Tighten Tighten the exhaust manifold bolts - First Pass to 15 N.m (11 ft lbs). Tighten the exhaust manifold bolts - Second Pass to 30 N.m (22 ft lbs).
4. Install the spark plugs.
5. Install the spark plug wires to the spark plugs.
6. Install the spark plug wire support and bolts. Tighten Tighten the spark plug wire support bolts to 12 N.m (106 in lbs).
7. Install the EGR valve inlet pipe to the exhaust manifold. Tighten Tighten the EGR valve inlet pipe exhaust manifold nut to 30 N.m (22 ft lbs).
8. Install the catalytic converter assembly. Refer to «Catalytic Converter Replacement (4.3L)»(/chevrolet/chevy-express-h2500/2003-2003/remont/exhaust/#engine-exhaust-system) or «Catalytic Converter Replacement (Dual Exhaust - Right)»(/chevrolet/chevy-express-h2500/2003-2003/remont/exhaust/#engine-exhaust-system) or «Catalytic Converter Replacement (Dual Exhaust - Left)»(/chevrolet/chevy-express-h2500/2003-2003/remont/exhaust/#engine-exhaust-system) .
9. Install the fender wheelhouse extension (1).
10. Install the left front tire.
11. Lower the vehicle.
12. Connect the ECT gage sensor electrical connector.
13. Install the engine cover.

Scheme 16

1. Raise the vehicle.
2. Remove the catalytic converter from the exhaust manifold. Refer to «Catalytic Converter Replacement (4.3L)»(/chevrolet/chevy-express-h2500/2003-2003/remont/exhaust/#engine-exhaust-system) or «Catalytic Converter Replacement (Dual Exhaust - Right)»(/chevrolet/chevy-express-h2500/2003-2003/remont/exhaust/#engine-exhaust-system) or «Catalytic Converter Replacement (Dual Exhaust - Left)»(/chevrolet/chevy-express-h2500/2003-2003/remont/exhaust/#engine-exhaust-system) .
3. Remove the engine cover.
4. Disconnect the EGR valve pipe from the exhaust manifold if equipped.
5. Remove the spark plug wires.
6. Remove the exhaust manifold.
7. Clean all sealing surfaces.

Scheme 17

1. Install the exhaust manifold. Tighten Tighten the exhaust manifold bolts - First Pass to 15 N.m (11 ft lbs). Tighten the exhaust manifold bolts - Second Pass to 25 N.m (18 ft lbs).
2. Connect the EGR valve pipe to the manifold.
3. Install the spark plug wires.
4. Install the exhaust pipe to the exhaust manifold.
5. Install the engine cover.

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1. Raise the vehicle.
2. Remove the right front tire.
3. Remove the right fender wheelhouse extension (1).
4. Disconnect the spark plug wires from the spark plugs.
5. Remove the bolts and the spark plug wire support.
6. Remove the starter. Refer to «STARTER MOTOR REPLACEMENT (4.3L)»(/chevrolet/chevy-express-h2500/2003-2003/remont/starter/#starting-system__starter-motor-replacement-43l) or «STARTER MOTOR REPLACEMENT (4.8L, 5.3L & 6.0L)»(/chevrolet/chevy-express-h2500/2003-2003/remont/starter/#starting-system__starter-motor-replacement-48l-53l) .
7. Remove the catalytic converter assembly. Refer to «Catalytic Converter Replacement (4.3L)»(/chevrolet/chevy-express-h2500/2003-2003/remont/exhaust/#engine-exhaust-system) or «Catalytic Converter Replacement (Dual Exhaust - Right)»(/chevrolet/chevy-express-h2500/2003-2003/remont/exhaust/#engine-exhaust-system) or «Catalytic Converter Replacement (Dual Exhaust - Left)»(/chevrolet/chevy-express-h2500/2003-2003/remont/exhaust/#engine-exhaust-system) .
8. Remove the exhaust manifold bolts through the wheelhouse.
9. Remove the exhaust manifold with the exhaust manifold gaskets and the spark plug wire shields from the engine.
10. Clean all gasket surfaces.

Important: To assist in installing the exhaust manifold to the engine, the tabs on a NEW exhaust manifold gasket will hold the gasket and the bolts in place.

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1. Sub-assemble the NEW gaskets, the spark plug wire shields, and the bolts to the exhaust manifold.
2. Ensure that the exhaust manifold bolts are held in place by the tabs on the exhaust manifold gaskets. CAUTION: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.
3. Install the exhaust manifold. Tighten Tighten the exhaust manifold bolts - First Pass to 15 N.m (11 ft lbs). Tighten the exhaust manifold bolts - Second Pass to 30 N.m (22 ft lbs).
4. Install the catalytic converter assembly. Refer to «Catalytic Converter Replacement (4.3L)»(/chevrolet/chevy-express-h2500/2003-2003/remont/exhaust/#engine-exhaust-system) or «Catalytic Converter Replacement (Dual Exhaust - Right)»(/chevrolet/chevy-express-h2500/2003-2003/remont/exhaust/#engine-exhaust-system) or «Catalytic Converter Replacement (Dual Exhaust - Left)»(/chevrolet/chevy-express-h2500/2003-2003/remont/exhaust/#engine-exhaust-system) .
5. Install the starter. Refer to «STARTER MOTOR REPLACEMENT (4.3L)»(/chevrolet/chevy-express-h2500/2003-2003/remont/starter/#starting-system__starter-motor-replacement-43l) or «STARTER MOTOR REPLACEMENT (4.8L, 5.3L & 6.0L)»(/chevrolet/chevy-express-h2500/2003-2003/remont/starter/#starting-system__starter-motor-replacement-48l-53l) .
6. Install the spark plug wire support and bolts. Tighten Tighten the spark plug wire support bolts to 12 N.m (106 in lbs).
7. Install the spark plug wires.
8. Install the fender wheelhouse extension (1).
9. Install the front tire. Refer to «TIRE AND WHEEL REMOVAL AND INSTALLATION»(/chevrolet/chevy-express-h2500/2003-2003/remont/wheel-tire-system/#tires-wheels__tire-and-wheel-removal-and-installation) .
10. Lower the vehicle.

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1. Remove the catalytic converter from the exhaust manifold. Refer to «Catalytic Converter Replacement (4.3L)»(/chevrolet/chevy-express-h2500/2003-2003/remont/exhaust/#engine-exhaust-system) or «Catalytic Converter Replacement (Dual Exhaust - Right)»(/chevrolet/chevy-express-h2500/2003-2003/remont/exhaust/#engine-exhaust-system) or «Catalytic Converter Replacement (Dual Exhaust - Left)»(/chevrolet/chevy-express-h2500/2003-2003/remont/exhaust/#engine-exhaust-system) .
2. Remove the engine cover.
3. Remove the oil level indicator tube. Refer to «OIL LEVEL INDICATOR AND TUBE REPLACEMENT»(/chevrolet/chevy-express-h2500/2003-2003/remont/mechanical/#engine-mechanical-48l-53l-60l) .
4. Remove the exhaust manifold bolts and exhaust manifold.
5. Clean all sealing surfaces.

Scheme 25

1. Install the exhaust manifold and bolts. Tighten Tighten the exhaust manifold bolts - First Pass to 15 N.m (11 ft lbs). Tighten the exhaust manifold bolts - Second Pass to 25 N.m (18 ft lbs).
2. Install the oil level indicator tube. Refer to «OIL LEVEL INDICATOR AND TUBE REPLACEMENT»(/chevrolet/chevy-express-h2500/2003-2003/remont/mechanical/#engine-mechanical-48l-53l-60l) .
3. Install the catalytic converter to the exhaust manifold.
4. Install the engine cover.

Scheme 26

1. Raise and suitably support the vehicle. WARNING: In order to avoid being burned, do not service the exhaust system while it is still hot. Service the system when it is cool. WARNING: Always wear protective goggles and gloves when removing exhaust parts as falling rust and sharp edges from worn exhaust components could result in serious personal injury.
2. Remove the catalytic converter pipe to exhaust manifold flange nuts.
3. Remove the catalytic converter pipe from the exhaust manifold.
4. Remove and discard the seal.
5. Inspect the exhaust manifold studs for damage.
6. Remove any damaged studs.

Scheme 27

1. Install any studs that were removed. Tighten Tighten the exhaust manifold studs to 18 N.m (13 ft lbs).
2. Install the catalytic converter pipe and NEW seal to the exhaust manifold.
3. Install the catalytic converter pipe to exhaust manifold flange nuts. Tighten Tighten the catalytic converter pipe to manifold flange bolts to 65 N.m (48 ft lbs).
4. Lower the vehicle. CAUTION: When inspecting or replacing exhaust system components, make sure there is adequate clearance from all points on the underbody to prevent overheating of the floor pan and possible damage to the passenger compartment insulation and trim materials.
5. Inspect for any exhaust leaks and proper alignment of the exhaust system.

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1. Raise the vehicle.
2. Disconnect the heated oxygen sensor (HO2S) electrical connections from catalytic converter pipe.
3. Remove the exhaust hanger bolts and hanger from the transmission.
4. Remove the nuts and the seals retaining the catalytic converter pipe to the exhaust manifolds. WARNING: In order to avoid being burned, do not service the exhaust system while it is still hot. Service the system when it is cool. WARNING: Always wear protective goggles and gloves when removing exhaust parts as falling rust and sharp edges from worn exhaust components could result in serious personal injury.
5. Remove the flange nuts from the catalytic pipe to the muffler.
6. Remove the catalytic converter from the vehicle.
7. Remove the oxygen sensors as necessary. Refer to «OXYGEN SENSOR»(/chevrolet/chevy-express-h2500/2003-2003/remont/removal-installation/#engine-controls-removal-installation-gasoline) .

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1. Install the oxygen sensors as necessary. Refer to «OXYGEN SENSOR»(/chevrolet/chevy-express-h2500/2003-2003/remont/removal-installation/#engine-controls-removal-installation-gasoline) .
2. Position the catalytic pipe to the vehicle.
3. Install the retaining nuts to the front of the muffler. Do not tighten the nuts. CAUTION: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.
4. Install the new seals, the nuts and the exhaust pipe flange to exhaust manifold. Tighten Tighten the exhaust pipe flange to exhaust manifold nuts to 65 N.m (48 ft lbs). Tighten the catalytic converter to muffler retaining nuts to 48 N.m (35 ft lbs).
5. Connect the HO2S electrical connections.
6. Install the exhaust hanger and bolts to the transmission. Tighten Tighten the bolts to 17 N.m (13 ft lbs). CAUTION: When inspecting or replacing exhaust system components, make sure there is adequate clearance from all points on the underbody to prevent overheating of the floor pan and possible damage to the passenger compartment insulation and trim materials.
7. Verify the exhaust system for proper clearance and the alignment of all components.
8. Lower the vehicle.

Scheme 32

1. Raise the vehicle.
2. Disconnect the oxygen sensor connectors.
3. Remove the exhaust hanger bolts and hanger from the vehicle. WARNING: In order to avoid being burned, do not service the exhaust system while it is still hot. Service the system when it is cool. WARNING: Always wear protective goggles and gloves when removing exhaust parts as falling rust and sharp edges from worn exhaust components could result in serious personal injury.
4. Remove the nuts retaining the exhaust pipe flange to the catalytic converter pipe.
5. Loosen the nut retaining the exhaust pipe clamp to the muffler.
6. Remove the exhaust pipe and flange gasket.

Scheme 33

1. Remove the oxygen sensors and install into new exhaust pipe. Tighten Tighten the sensors to 42 N.m (31 ft lbs).
2. Install new gasket to the catalytic converter pipe flange.
3. Install the exhaust pipe to the vehicle.
4. Install the nuts for the catalytic converter pipe to exhaust pipe. Tighten Tighten the flange nuts to 48 N.m (35 ft lbs).
5. Tighten the exhaust pipe clamp nut. Tighten Tighten the nut to 54 N.m (40 ft lbs). CAUTION: When inspecting or replacing exhaust system components, make sure there is adequate clearance from all points on the underbody to prevent overheating of the floor pan and possible damage to the passenger compartment insulation and trim materials.
6. Verify the exhaust system for proper clearance and the alignment of all components.
7. Install the exhaust hanger and bolts. Tighten Tighten the bolts to 17 N.m (13 ft lbs).
8. Lower the vehicle.

Scheme 34

1. Raise the vehicle.
2. Disconnect the oxygen sensors.
3. Remove the exhaust hanger bolts and hanger from the vehicle. WARNING: In order to avoid being burned, do not service the exhaust system while it is still hot. Service the system when it is cool. WARNING: Always wear protective goggles and gloves when removing exhaust parts as falling rust and sharp edges from worn exhaust components could result in serious personal injury.
4. Remove the nuts retaining the exhaust pipe flange to the catalytic converter pipe.
5. Remove the nuts retaining the exhaust pipe flange to the muffler.
6. Remove the exhaust pipe.
7. Remove the flange gasket.

Scheme 35

1. Remove the oxygen sensors and install into the new exhaust pipe. Tighten Tighten the sensors to 42 N.m (31 ft lbs).
2. Install new gaskets to the muffler flange and the catalytic converter pipe flange.
3. Install the exhaust pipe.
4. Install the nuts for the catalytic converter pipe to the exhaust pipe. Tighten Tighten the flange nuts to 48 N.m (35 ft lbs).
5. Install the nuts for the muffler to the exhaust pipe. Tighten Tighten the nuts to 48 N.m (35 ft lbs).
6. Connect the oxygen sensor connectors.
7. Install the exhaust hanger and bolts. Tighten Tighten the bolts to 17 N.m (13 ft lbs). CAUTION: When inspecting or replacing exhaust system components, make sure there is adequate clearance from all points on the underbody to prevent overheating of the floor pan and possible damage to the passenger compartment insulation and trim materials.
8. Verify the exhaust system for proper clearance and the alignment of all components.
9. Lower the vehicle.

Scheme 36

1. Raise and suitably support the vehicle. WARNING: In order to avoid being burned, do not service the exhaust system while it is still hot. Service the system when it is cool. WARNING: Always wear protective goggles and gloves when removing exhaust parts as falling rust and sharp edges from worn exhaust components could result in serious personal injury.
2. Remove the exhaust hanger bolts from the transmission.
3. Using a suitable pry bar, remove the applicable hanger pin attached to the pipe from the exhaust hanger insulator.
4. Remove the hanger from the vehicle.

Scheme 37

1. Install the exhaust pipe hanger pins in the exhaust hanger insulator.
2. Install the exhaust hanger to the transmission. CAUTION: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.
3. Install the exhaust hanger bolts. Tighten Tighten the exhaust hanger bolts to 17 N.m (13 ft lbs). CAUTION: When inspecting or replacing exhaust system components, make sure there is adequate clearance from all points on the underbody to prevent overheating of the floor pan and possible damage to the passenger compartment insulation and trim materials.
4. Verify the exhaust system for proper clearance and the alignment of all components.
5. Lower the vehicle.

Muffler Replacement

Removal Procedure

Important: The muffler is serviced as one complete unit with an exhaust pipe and tail pipe. Some variations of vehicles may have an aftermarket tail pipe added. When the vehicle is raised on the hoist it must be raised by the frame to allow the rear axle to be lowered.

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1. Raise the vehicle.
2. If equipped with 4.3L engine with a single catalytic converter pipe, remove the nuts retaining the catalytic converter pipe from the muffler flange.
3. If equipped with a 4.8L/5.3L/6.0L engine with dual catalytic converter pipes, loosen the clamp for the right catalytic converter.
4. Remove the nuts retaining the left catalytic converter to the muffler flange. Important: Depending on the wheel base of the vehicle and the length of the exhaust system the following procedures are required in order to remove the muffler assembly from the vehicle.
5. Remove the muffler assembly hanger pins from the exhaust hanger insulators. Due to the weight of the exhaust system it may take 2 persons.
6. Remove the muffler assembly by lifting over the rear axle and remove towards the front of the vehicle.

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1. Install the muffler assembly from the front of the vehicle by lifting over the rear axle. Due to the weight of the exhaust system it may take 2 persons.
2. Install the muffler assembly hanger pins to the exhaust hanger insulators. CAUTION: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.
3. If equipped with a 4.3L engine, install the retaining nuts and new gasket to the front of the muffler. Tighten Tighten the catalytic converter to muffler retaining nuts to 48 N.m (35 ft lbs).
4. If equipped with a 4.8L/4.3L/6.0L engine, install the right catalytic converter in the muffler. Tighten Tighten the clamp nut to 54 N.m (40 ft lbs).
5. Install a new gasket and the nuts retaining the left catalytic converter to the muffler flange. Tighten Verify that the exhaust system is properly aligned and tighten the right catalytic converter clamp to 54 N.m (40 ft lbs). Tighten the catalytic converter to the muffler flange nuts to 48 N.m (35 ft lbs).
6. Lower the vehicle.

Exhaust Heat Shield Replacement - Body Panel

Tools Required

J 34940 Rivet Gun

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1. Raise the vehicle.
2. Using a 1/4 inch (6 mm) drill bit, remove the rivets from the heat shields, as necessary.
3. Remove the exhaust tailpipe heat shield from the vehicle.
4. Remove the exhaust tailpipe heat shield from the vehicle.
5. Remove the muffler heat shield.
6. Remove the muffler heat shield.
7. Remove the front exhaust pipe heat shield.
8. Remove the front exhaust pipe heat shield.

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1. Install the front exhaust pipe heat shield on the vehicle.
2. Install the rivets on the heat shield using the J 34940 .
3. Install the front exhaust pipe heat shield on the vehicle.
4. Install the rivets on the heat shield using the J 34940 .
5. Install the muffler heat shield on the vehicle.
6. Install the rivets on the heat shield using the J 34940 .
7. Install the muffler heat shield on the vehicle.
8. Install the rivets on the heat shield using the J 34940 .
9. Install the exhaust tailpipe heat shield on the vehicle.
10. Install the rivets on the heat shield using the J 34940 .
11. Install the exhaust tailpipe heat shield on the vehicle.
12. Install the rivets on the heat shield using the J 34940 .
13. Lower the vehicle.

Scheme 56

1. Raise and suitably support the vehicle with safety stands.
2. Remove the exhaust system, as necessary.
3. Remove the bolts retaining the heat shield.
4. Remove the heat shield.

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1. Install the heat shield. CAUTION: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.
2. Install the heat shield bolts. Tighten Tighten the heat shield retainer bolt to 12 N.m (106 in lbs).
3. Install the exhaust system, as necessary.
4. Remove the safety stands and lower the vehicle.

Exhaust System Description

Important: 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.

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See also:
• STARTER MOTOR REPLACEMENT (4.3L)
• STARTER MOTOR REPLACEMENT (4.8L, 5.3L & 6.0L)
• TIRE AND WHEEL REMOVAL AND INSTALLATION
• OIL LEVEL INDICATOR AND TUBE REPLACEMENT
• OXYGEN SENSOR
• Symptoms - Engine Exhaust
• Exhaust System Description
• Restricted Exhaust
• Exhaust Leakage