Exhaust System: Description and Operation
EXHAUST SYSTEMSExhaust System:
The exhaust system has an underfloor catalytic converter, tail pipe, and muffler.
EXHAUST BALL JOINT COUPLING
Ball Joint Connection:
An exhaust ball joint coupling is used to secure the exhaust pipe to the engine exhaust manifold. This flexible joint 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 ball joint consists of two bolts, two springs, and a ball joint seal ring, which is a separate part from the exhaust pipe.
EXHAUST FLEX-JOINT COUPLING (LEV)
Flex-Joint (LEV):
An exhaust flex joint coupling is used on Low Emission Vehicles (LEV). This coupling is used to secure the catalytic converter to the exhaust manifold. This coupling 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.
CATALYTIC CONVERTER
Exhaust System Components-Typical:
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.
The combustion reaction caused by the catalyst releases additional heat in the exhaust system. Causing temperature increases in the area of the reactor 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 a 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 above 1200 RPM in neutral for extended periods over 5 minutes. This condition may result in excessive exhaust system/floor pan temperatures because of no air movement under the vehicle.
HEAT SHIELDS
Heat Shield Installation:
The heat shield is needed to protect both the car and the environment from the high temperatures developed in the vicinity of the catalytic converter.
CAUTION: Avoid application of rust prevention compounds or undercoating materials to exhaust system floor pan heat shield on cars if 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.
EXHAUST GAS RECIRCULATION (EGR) SYSTEM
To assist in the control of Oxides Of Nitrogen (NOx) in engine exhaust, some 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 the number four exhaust port through a hole in the end of the cylinder head.