Exhaust System: Description and Operation

EXHAUST SYSTEM
The exhaust system provides an exit for exhaust gases and reduces engine noise by passing exhaust gases through the three way catalytic converter (TWC), a muffler inlet pipe and resonator and a muffler.. Rubber exhaust hanger insulators attach the exhaust system to the mounting hooks.

Three Way Catalytic Converter (TWC)
The three way catalytic converter (TWC) plays a major role in the emission control system. The TWC operates as a gas reactor. Its catalytic function is to speed the heat-producing chemical reaction of components in the exhaust gases in order to reduce air pollutants.
The catalyst material inside the TWC consists of a ceramic substrate.

Precautions

Warning:
^ The normal operating temperature of the exhaust system is very high. Never work around or attempt to repair any part of the exhaust system until it has cooled. Use special care when working around the TWC. The TWC heats to a high temperature after only a short period of engine operation. Failure to follow these instructions may result in personal injury.

Warning:
^ Exhaust gases contain carbon monoxide which can be harmful to health and are potentially lethal. Exhaust system leaks should be repaired immediately. Never operate the engine in enclosed areas. Failure to follow these instructions may result in personal injury.

Caution:
^ Do not use leaded fuel in a vehicle equipped with a TWC.

Caution:
^ In a vehicle that is continually misfueled, the lead in the fuel will be deposited in the TWC and completely blanket the catalyst. Lead reacts with platinum to "poison" the catalyst. Continuous use of leaded fuel can destroy the catalyst and render the TWC useless.

Caution:
^ The addition of lead to the TWC can also solidify the catalyst, causing excessive back pressure in the exhaust system and possibly causing engine damage.

Caution:
^ Extremely high temperatures of 1,100°C (2,012°F) or above due to misfiring or an over-rich fuel/air mixture will cause the ceramic base to sinter or burn, destroying the TWC.

The TWC is designed to provide a long life. No maintenance is necessary for the TWC. Avoid the following conditions:
^ Driving with a misfiring engine.
^ Continuously running the engine with a misfiring spark plug.
^ Parking or stopping the vehicle over combustible material such as dry grass. The material can be ignited by the high temperatures of the TWC and of the muffler.

Sound Insulators and Shields
Sound insulators and shields attached to the underbody protect the vehicle from exhaust system heat and should be inspected at regular intervals to ensure they are not dented or out of position. If a sound insulator and shield is damaged or shows evidence of deterioration, it should be replaced. The sound insulators and shields for the muffler, muffler pipe, resonator, and TWC pipe are installed separately.