Scheme 1
| 1 - ISOLATOR |
|---|
| 2 - MUFFLER/RESONATOR ASSEMBLY |
| 3 - CATALYTIC CONVERTER |
| 4 - BAND CLAMP |
The exhaust system on the 2.4L/3.6L single exhaust engine models consists of a front mounted catalytic converter, resonator/pipe assembly, muffler/pipe assembly, band clamps, and support isolators. The upstream oxygen sensor is located in the exhaust manifold. The downstream oxygen sensor is located in the catalytic converter.
Scheme 2
| 1 - ISOLATOR |
|---|
| 2 - MUFFLER/RESONATOR ASSEMBLY - 3.6L |
| 3 - CATALYTIC CONVERTER |
| 4 - BAND CLAMP |
The exhaust system of a 3.6L dual exhaust consists of front and rear bank catalytic converters, cross-under pipe, connector pipe, resonator/pipe assembly, muffler/pipe assembly, band clamps, and support isolators. The upstream oxygen sensors are located in the front and rear exhaust manifolds. The downstream oxygen sensors are located in the cross-under pipe.
Resonators, mufflers, and exhaust pipes are tuned to each powertrain combination.
| CONDITION | POSSIBLE CAUSES | CORRECTION |
|---|---|---|
| EXCESSIVE EXHAUST NOISE (UNDER HOOD) | 1. Exhaust manifold cracked or broken. | 1. Replace manifold. |
| 2. Manifold to cylinder head leak. | 2. Tighten manifold and/or replace gasket. | |
| 3. EGR Valve to manifold gasket leakage. | 3. Tighten fasteners or replace gasket. | |
| 4. EGR Valve to EGR tube gasket leakage. | 4. Tighten fasteners or replace gasket. | |
| 5. EGR tube to manifold tube leakage. | 5. Tighten tube nut. | |
| 6. Exhaust flex-joint to manifold leak. | 6. Tighten joint fasteners and/or replace gasket. | |
| 7. Exhaust flex-joint. | 7. Replace catalytic converter assembly. | |
| 8. Pipe and shell noise from front exhaust pipe. | 8. Characteristic of single wall pipe. | |
| EXCESSIVE EXHAUST NOISE | 1. Leak at exhaust pipe joints. | 1. Tighten clamps at leaking joints. |
| 2. Burned or rusted out muffler assembly or exhaust pipe. | 2. Replace muffler resonator tailpipe assembly or exhaust pipe with catalytic converter assembly. | |
| 3. Burned or rusted out resonator. | 3. Replace muffler resonator tailpipe assembly. | |
| 4. Restriction in exhaust system. | 4. Perform Exhaust System Restriction Check. Replace component as necessary. | |
| 5. Converter material in muffler. | 5. Replace muffler and converter assemblies. Check fuel injection and ignition systems for proper operation. |
DESCRIPTION
| WARNING | The normal operating temperature of the exhaust system is very high. Therefore, never work around or attempt to service any part of the exhaust system until it is cooled. Special care should be taken when working near the catalytic converter. The temperature of the converter rises to a high level after a short period of engine operation time. |
| CAUTION | DO NOT remove spark plug wires from plugs or by any other means short out cylinders. Failure of the catalytic converter can occur due to a temperature increase caused by unburned fuel passing through the converter. |
The stainless steel catalytic converter body is designed to last the life of the vehicle. Excessive heat can result in bulging or other distortion, but excessive heat will not be the fault of the converter. If unburned fuel enters the converter, overheating may occur. If a converter is heat-damaged, correct the cause of the damage at the same time the converter is replaced. Also, inspect all other components of the exhaust system for heat damage.
Unleaded gasoline must be used to avoid contaminating the catalyst core.
Scheme 3
| 1 - ISOLATOR |
|---|
| 2 - MUFFLER/RESONATOR ASSEMBLY |
| 3 - CATALYTIC CONVERTER |
| 4 - BAND CLAMP |
| WARNING | The normal operating temperature of the exhaust system is very high. Therefore, never work around or attempt to service any part of the exhaust system until it is cooled. Special care should be taken when working near the catalytic converter. The temperature of the converter rises to a high level after a short period of engine operation time. |
Scheme 4
- Raise and support vehicle.
- Apply penetrating oil to resonator/pipe assembly band clamp (4), and the fasteners that connect the catalytic converter to the exhaust manifold.
- Remove ground strap from muffler.
- Loosen band clamp for resonator/pipe assembly (4). CAUTION: Do not use any tools to remove the rubber isolators, remove by hand only. Soapy water or silicone based lubricant spray may be used to assist removal/installation of isolators. DO NOT use a petroleum based lubricant on the isolators, as damage to the rubber material can occur.
- Remove support isolators from muffler/resonator assembly supports.
- Remove muffler/resonator pipe as an assembly. 1 - OXYGEN SENSOR ELECTRICAL CONNECTOR 2 - FLANGE NUTS 3 - CATALYTIC CONVERTER - 2.4L
- Disconnect oxygen sensor connector (1).
- Remove flange nuts at exhaust manifold.
- Remove catalytic converter from vehicle (3).
- Remove and discard gasket.
Scheme 5
Scheme 6
- Remove the cross-under pipe (4) from vehicle. Refer to «PIPE, EXHAUST CROSSUNDER, REMOVAL»(ref-485503-S41492710422012071300000) . NOTE: The lower bolts for the converter flange are used to hold a guide retainer plate (4). The retainer does not need to be removed. The catalytic converter (3) is held in by the plate and upper bolts.
- Disconnect the temperature and oxygen sensor electrical connectors.
- Remove the catalytic converter (3) to exhaust manifold (1) upper bolts (2).
- Remove the catalytic converter (3) by lifting and sliding the flange up and away from the exhaust manifold (1).
- Remove the temperature and oxygen sensors.
The exhaust system heat shields are attached to the under body of the vehicle.
OPERATION
Heat shields are needed to protect both the vehicle and the environment from the high temperatures developed near the catalytic converter.
Avoid application of rust prevention compounds or undercoating materials to exhaust system floor pan heat shields on vehicles so equipped. Light over spray near the edges is permitted. Application of coating will greatly reduce the efficiency of the heat shields resulting in excessive floor pan temperatures and objectionable fumes.