GM Service Manual Online
For 1990-2009 cars only

Caution: Refer to Hot Exhaust System Caution in the Preface section.

Notice: When you are inspecting or replacing exhaust system components, make sure there is adequate clearance from all points on the underbody to avoid possible overheating of the floor pan and possible damage to the passenger compartment insulation and trim materials.

Check the complete exhaust system and the nearby body areas and tailgate for broken, damaged, missing or mispositioned parts, open seams, holes, loose connections or other deterioration which could permit exhaust fumes to seep into the luggage or passenger compartment. Dust or water in the luggage may be an indication of a problem in one of these areas. Any defects should be corrected immediately.

Muffler

The muffler reduces the temperature, pressure, and noise of the exhaust gas.

Aside from the exhaust manifold connection, the exhaust system uses a flange and seal joint design opposed to a slip joint coupling design with clamp. If holes, open seams or any deterioration is discovered upon inspection of the front muffler and pipe assembly, the complete assembly should be replaced. The same procedure is applicable to the rear muffler assembly.

Heat shields in the front and rear muffler assembly positions, as well as for the catalytic converter and front exhaust pipe, protect the vehicle and the environment from high temperatures the exhaust system develops.

Catalytic Converter

Notice: When jacking or lifting the vehicle from the body side rails, be certain that the lift pads do not contact the catalytic converter as this could damage the catalytic converter.

Notice: The catalytic converter requires the use of unleaded fuel only, or damage to the catalyst will result.

Notice: Refer to Emission Modification Notice in the Preface section.

The catalytic converter is an emission control device added to the exhaust system to reduce pollutants from the exhaust pipes.

The oxidation catalyst is coated with a catalytic material containing platinum and palladium, which reduces levels of hydrocarbon (HC) and carbon monoxide (CO) from the exhaust gas. The 3-way catalyst has coatings which contain platinum and rhodium, which additionally lower the levels of oxides of nitrogen (NOx).