Exhaust System: Description and Operation

Exhaust System:

The exhaust systems consists of two front exhaust pipes equipped with close coupled metallic catalytic converters, muffler and tailpipes. The catalytic converters mount directly to the exhaust manifolds using a V-Band clamp. The muffler has two inlets that attach to the catalytic converter pipes. The tailpipes attach to the muffler's two outlets. These connections are retained by Band (Torca) clamps.
The exhaust system must be properly aligned to prevent undue stress, leakage and body contact. If the system contacts any other vehicle component, it may amplify objectionable noises originating from the engine or other components. These contacts could also be detrimental to the performance of the affected component.
When inspecting an exhaust system, inspect for cracked or loose joints, stripped threads, corrosion damage, and worn, cracked or broken hangers. Replace all components that are badly corroded or damaged. Do not attempt to repair.

Exhaust Manifold Coupling

V - Band Clamp:

The exhaust manifold to catalytic converter connection is secured by a V-Band clamp. When torque is applied to the V-Band clamp, it forces the flared mating surfaces of the manifold and catalytic converter together, to support and seal the joint. The V-Band clamp must be replaced if removed.

Catalytic Converters
The exhaust system uses two front close coupled metallic catalytic converters. Both converters mount directly to the exhaust manifolds using a V-Band clamp.
There is no regularly scheduled maintenance on any Chrysler catalytic converter. Excessive heat may cause bulging or other distortion, but excessive heat will not be the fault of the converter. A fuel system or ignition system malfunction that permits unburned fuel to enter the converter will usually cause overheating. If a converter is heat damaged, correct the cause of the damage at the same time the converter is replaced. The entire converter must be replaced. Inspect all other components of the exhaust system for heat damage. Unleaded gasoline must be used to avoid damage to the catalyst core.

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

Heat Shields
Heat shields are needed to protect both the car and the environment from the high temperatures developed in the vicinity of the exhaust manifolds, catalytic converters, and muffler. The exhaust manifolds use a two piece, double wall, aluminized steel heat shield. Each catalytic converter has a integral heat shield attached to it and are not to be removed.

CAUTION: Avoid application of rust prevention compounds or undercoating materials to exhaust system heat shields 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.

The combustion reaction caused by the catalyst releases additional heat in the exhaust system. Causing the temperature to increase 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 ignition coils 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 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.

Exhaust Supports

Exhaust Support Bracket:

The exhaust system is supported at four locations by isolators and support brackets. The lower support brackets are welded to the tailpipes. The upper, frame mounted support brackets are riveted to the frame using two special rivets per each bracket.

Exhaust Gas Recirculation (EGR) System
To assist in the control of Oxides Of Nitrogen (NOx) in engine exhaust, this engine is 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 five cylinder's exhaust port through a passage in the rear of the cylinder head. The exhaust gas flow is metered by the EGR valve into the intake manifold plenum through a tube. Refer to Powertrain Management for a complete description, diagnosis and service procedures on the exhaust gas recirculation system and components.