GM Service Manual Online
For 1990-2009 cars only

The exhaust system is used to carry and treat the gases that are created by the engine. When the engine exhaust valve opens hot gases created by the engine combustion cycle are allowed to travel out through the cylinder head into the exhaust manifold. In the exhaust manifold the exhaust gases combine with exhaust gases from the other cylinders and pass through a flanged port into the three-way catalytic converter pipe. The exhaust gases pass through the catalytic converter to reduce pollutants from the exhaust stream gases. The three-way catalytic converter pipe carries the exhaust gases on to the exhaust system where the resonator and muffler are used to reduce the noise levels of the exhaust. The exhaust system exits at the rear of the vehicle to reduce exhaust noise and prevent fumes from entering the vehicle. Exhaust system hangers and insulators support the weight of the exhaust system, isolate engine noise, isolate engine vibration, space the system away from the underbody of the vehicle and allow for exhaust system expansion that occurs as the exhaust system warms up.