Exhaust System: Description and Operation

Fig. 1 Exhaust System:

EXHAUST SYSTEMS - GENERAL INFORMATION
The exhaust system is produced in one configuration. The system has a front mounted catalytic converter, muffler and resonator. Tail pipes, mufflers, and resonators are tuned to each powertrain combination.

CATALYTIC CONVERTERS
There is no regularly scheduled maintenance on any Chrysler catalytic converter. If damaged, the converter must be replaced.

CAUTION: Due to exterior physical similarities of some catalytic converters with pipe assemblies, extreme care should be taken with replacement parts. There are internal converter differences required in some parts of the country (particularly California vehicles).

Fig. 2 Flex-Joint Coupling:

EXHAUST FLEX - JOINT COUPLING
A exhaust flex-joint coupling is used to secure the catalytic converter to the engine manifold. This living joint actually moves back and forth as the engine moves, preventing breakage that could occur from the back-and-forth motion of a transverse mounted engine.

The exhaust flex-joint is welded to the catalytic converter.


CAUTION: When servicing, care must be exercised not to dent or bend the bellows of the flex-joint. Should this occur, the flex-joint will eventually fail and require the catalytic converter be replaced.

Fig. 3 Ball Joint Connection:

EXHAUST BALL - JOINT COUPLING
A exhaust ball joint coupling is used to secure the exhaust pipe to the engine manifold. This living joint actually moves back and forth as the engine moves, preventing breakage that could occur from the back-and-forth motion of a transverse mounted engine.

EXHAUST GAS RECIRCULATION (EGR)
To assist in the control of Oxides of Nitrogen (NOx) in engine exhaust, all engines are equipped with an exhaust gas recirculation system. The use of exhaust gas to dilute incoming air/fuel mixtures lowers peak flame temperatures during combustion, thus limiting the formation of NOx.

Exhaust gases are taken from opening in the exhaust manifold passage to the intake manifold.

Fig. 4 Heat Shields:

HEAT SHIELDS
Heat shields are needed to protect both the vehicle and the environment from the high temperatures developed near the catalytic converters. All engines are equipped with a heat shield crimped on the top of the convertor.

Avoid application of rust prevention compounds or undercoating materials to exhaust system floor pan heat shields on cars 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.

The combustion reaction caused by the catalyst releases additional heat in the exhaust system. Causing temperature increases in the area of the catalytic convertor under severe operating conditions. Such conditions can exist when the engine misfires or otherwise does not operate at peak efficiency Do not remove spark plug wires from plugs or by any other means short out cylinders if exhaust system is equipped with catalytic converter. Failure of the catalytic converter can occur due to temperature increases caused by unburned fuel passing through the converter.

The use of the catalysts also involves some non-automotive problems. Unleaded gasoline must be used to avoid poisoning the catalyst core. Do not allow engine to operate at fast idle for extended periods (over 5 minutes). This condition may result in excessive exhaust system and floor pan temperatures.