Exhaust System: Description and Operation
EXHAUST SYSTEMWARNING: 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.
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The exhaust system has a front mounted catalytic converter with flexjoint, center mounted resonator, and rear muffler. Band clamps are used in two locations to connect system components.
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 vehicles built for States with strict emission requirements).
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. Refer to Emission Control Systems for a complete Description, Diagnosis, and Service Procedures on the exhaust gas recirculation system and components.
HEAT SHIELDS
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Heat shields are needed to protect both the vehicle and the environment from the high temperatures developed near the catalytic converter. All engines are equipped with a heat shield crimped on the top of the converter.
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 converter 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.
EXHAUST SYSTEM GROUND STRAP
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All vehicles are equipped with a ground strap on the exhaust system. The ground strap is attached from the rear muffler bracket to the body. The ground strap is used to suppress radio frequency interference/static.
EXHAUST FLEX-JOINT COUPLING
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An exhaust flexjoint coupling and is used to secure the catalytic converter to the engine manifold. This 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 flexjoint is welded to the catalytic converter.
CAUTION: When servicing, care must be exercised not to dent or bend the bellows or bellows cover of the flex-joint. Should this occur, the flexjoint will eventually fail and require the catalytic converter be replaced.