GM Service Manual Online
For 1990-2009 cars only

Important: Use of non-OEM parts may cause driveability problems.

The exhaust system carries exhaust gases, treated by the catalytic converter, through a resonator, if equipped and into the exhaust muffler where exhaust noise is lessened.

In order to secure the exhaust pipe to the exhaust manifold, a flange and seal-joint coupling is utilized. The exhaust system may utilize a slip-joint coupling design with a clamp and a U-bolt or a flange connection with a gasket to connect.

Exhaust hangers and rubber insulators help to support the weight of the exhaust pipe along with insulating any exhaust system vibration, rattle, or noise.

Exhaust hangers also space the exhaust system away from the underbody of the vehicle, which allows the exhaust system to expand as the exhaust system warms up.

Exhaust heat shields are used to protect the body and other components from damage due to the heat from the exhaust system.

The exhaust system may be comprised of the following components:

    • Exhaust manifold
    • Exhaust pipes
    • Catalytic converters
    • Exhaust muffler
    • Exhaust resonator, if equipped
    • Exhaust tail pipe, if equipped
    • Exhaust hangers
    • Exhaust heat shields

Resonator

Some exhaust systems are equipped with a resonator. The resonator, located in front of muffler or behind the muffler, allows the use of mufflers with less back pressure. Resonators are used when vehicle characteristics require specific exhaust tuning.

Catalytic Converter

The catalytic converter is an emission control device added to the engine exhaust system in order to reduce hydrocarbons (HC), carbon monoxide (CO), and oxides of nitrogen (NOx) pollutants from the exhaust gas.

The catalytic converter is comprised of a ceramic monolith substrate, supported in insulation and housed within a sheet metal shell. The substrate may be washcoated with 3 noble metals:

    • Platinum (Pt)
    • Palladium (Pd)
    • Rhodium (Rh)

The catalyst in the converter is not serviceable.

Muffler

The exhaust muffler reduces the noise levels of the engine exhaust by the use of tuning tubes. The tuning tubes create channels inside the exhaust muffler that lower the sound levels created by the combustion of the engine.