Three-Way Converter (TWC)
The three-way converter (TWC) is an emission-control device that is added to the gasoline engine exhaust system. The TWC reduces hydrocarbon, carbon monoxide, and oxides of nitrogen (NOx) emissions.
The TWC has a honeycomb network that is coated with catalytic material of platinum, palladium and rhodium.
The catalytic material promotes burning or oxidation of the pollutants as the exhaust gases pass through the TWC on their way to the tail pipe.
Use only unleaded gasoline.
Use of unleaded gasoline has the following results:
| • | Reduces deposits in the combustion chamber and on the spark plug |
| • | Extends the life of the engine oil |
| • | Prevents lead contamination of the TWC that renders the TWC ineffective and causes loss of the emission system warranty coverage |
This exhaust system has two TWCs that are 150 cu in (2458.05 cu cm) each. Each TWC is a unit that is separate from the respective right or left exhaust manifold. The TWCs are mounted between the exhaust manifold and the exhaust resonator.
Three-Way Converter (TWC) Braces
The TWC braces are installed between the transmission and the TWC in order to eliminate undesirable noises from advancing to the vehicle. These braces are not servicable.
When re-installing the three-way converter, follow the proper procedures in order to avoid transmitting noises into the vehicle.
Mufflers
The mufflers on this car have a triflow design.
During muffler replacement on this exhaust system, it is not necessary to replace the resonator. However, during resonator replacement, replace the two mufflers.
During muffler replacement, carefully inspect the rear crossover pipe. Replace this pipe, if necessary.
Hangers
Two spring hangers support the exhaust system. One is in front of the resonator and is mounted to the transmission. The second hanger is behind the resonator and is mounted to the differential carrier. A blade and a block hanger on the frame support the mufflers.
The exhaust system supports prevent noises and vibrations from being transmitted into the passenger compartment. Supports that are improperly installed can cause vibrations that are difficult to diagnose.
Clamp and Weld
The clamp and the weld are two methods used in order to connect exhaust system slip joints. Cut a weld and clamp the new connection when installing replacement parts. Also, coat the slip joints with exhaust system sealer before assembly.
Exhaust Resonator Assembly
The exhaust resonator assembly consists of the front exhaust pipes, the resonator, and the rear exhaust pipes.The resonator and the pipes are serviced together and are not available as separate components.
The front exhaust pipes direct the engine exhaust gases from the two exhaust manifolds and the three-way converters (TWCs) into the resonator dual inlet pipes. The rear exhaust pipes direct the resonator outlet gases to the two mufflers.
