DESCRIPTION
| CAUTION | Avoid application of rust prevention compounds or undercoating materials to exhaust system floor pan exhaust heat shields. Light over-spray near the edges is permitted. Application of coating will result in excessive floor pan temperatures and objectionable fumes. |
The gasoline engine exhaust system consists of engine exhaust manifolds, exhaust pipes (4), catalytic converter(s) (5), extension pipe (if needed) (6), exhaust heat shields (7), muffler and exhaust tailpipe (1).
The exhaust system must be properly aligned to prevent stress, leakage and body contact. Minimum clearance between any exhaust component and the body or frame is 25.4 mm (1.0 in.). If the system contacts any body panel, it may amplify objectionable noises from the engine or body.
Scheme 1
OPERATION
The exhaust system channels exhaust gases from the engine and away from the vehicle.
| CONDITION | POSSIBLE CAUSE | CORRECTION |
|---|---|---|
| EXCESSIVE EXHAUST NOISE | Leaks at pipe joints. Burned or blown out muffler. Burned or rusted-out exhaust pipe. Exhaust pipe leaking at manifold flange. Exhaust manifold cracked or broken. Leak between exhaust manifold and cylinder head. Restriction in muffler or tailpipe. Exhaust system contacting body or chassis. | Tighten clamps to specified torque at leaking joints (Refer to SPECIFICATIONS ). Replace muffler assembly (Refer to REMOVAL ). Check exhaust system. Replace exhaust pipe (Refer to REMOVAL ). Tighten connection attaching nuts (Refer to SPECIFICATIONS ). Replace exhaust manifold (Refer to appropriate ENGINE article). Tighten exhaust manifold to cylinder head stud nuts or bolts (Refer to appropriate ENGINE article). Remove restriction, if possible. Replace muffler or tailpipe, as necessary. Re-align exhaust system to clear surrounding components. |
| LEAKING EXHAUST GASES | Leaks at pipe joints. | Tighten/replace clamps at leaking joints (Refer to SPECIFICATIONS ). |
EXHAUST SYSTEM DIAGNOSIS CHART
California emissions vehicles incorporate mini catalytic converters into the exhaust system. These catalytic converters are made of stainless steel designed to operate at extremely high temperatures.
The catalytic converter captures and burns any unburned fuel mixture exiting the combustion chambers during the exhaust stroke of the engine. This process aids in reducing emissions output.
There are two types of heat shields (1) used. One is stamped steel the other is molded foil sheets. The shields attach to the vehicle around the exhaust system.
Scheme 2
The heat shields prevent heat from the exhaust system from entering the passenger area and other areas where the heat can cause damage to other components.
Scheme 3
- Raise and support the vehicle.
- Remove the screws and nuts holding the heat shields (1) to the frame and floor pan. When removing muffler heat shield, the muffler front and rear support hangers (2) must be removed first. Be sure to disconnect both oxygen sensor connectors.
- Slide the heat shield (1) out around the exhaust system.
All engines use a stainless steel muffler (1) to control exhaust noise levels and exhaust back pressure.
Scheme 4
The muffler is designed to muffle the sound of the exhaust as if leaves the engine.
Scheme 5
- Raise vehicle on hoist.
- Remove the exhaust pipe (Refer to «TAILPIPE»(ref-212817-S09803397022005122700000) ).
- Remove the muffler-to-catalytic converter clamp (3).
- Remove the muffler isolators (1 and 4).
- Remove the muffler (5) from the catalytic converter.
The tailpipe is made of stainless steel and attaches to the muffler.
Scheme 6
The tailpipe channels the exhaust out of the muffler and out front under the vehicle to control noise and prevent exhaust gas fumes from entering the passenger compartment.