Notice: In order to prevent overheating of the floor panel or damage to the passenger compartment, insulation, and trim materials, check the underbody for adequate clearance when inspecting or replacing the exhaust system components.
The 3.8L (VIN K) engine equipped vehicles without RPO Y87 (performance enhancement package) use the following components:
| • | A three-way catalytic converter |
| • | A single outlet exhaust muffler |
The 3.8L (VIN K) engine equipped vehicles with RPO Y87 use the following components:
| • | A three-way catalytic converter |
| • | A dual outlet muffler |
The 5.7L (VIN G) engine equipped vehicles use the following components:
| • | A dual three-way plus oxidation catalytic converter (oxidation catalytic converter) |
| • | A dual outlet muffler |
Periodic maintenance of the exhaust system is not required. If the vehicle is raised for other service, check the condition of the complete exhaust system.
Inspect the complete exhaust system, nearby body parts, and the rear compartment lid for the following conditions:
| • | Broken or damaged parts |
| • | Mispositioned or missing parts |
| • | Open seams |
| • | Holes |
| • | Loose connections |
| • | Other deterioration that could permit exhaust fumes to seep into the rear compartment or the passenger compartment. |
Check the rear compartment for dust or water, which may indicate a problem in this area.
Correct any faulty areas immediately.
Catalytic Converter
Caution: Prolonged operation of a misfiring or flooded engine may cause the catalytic converter to overheat. Damage to the catalyst, the operating vehicle, or personal injury may result.
Notice: When jacking or lifting the vehicle from the frame side rails, be certain that the lift pads do not contact the catalytic converter. This may damage the converter.
Notice: In order to avoid damage to the catalyst, use unleaded fuel only.
The catalytic converter is an emission control device added to the exhaust system in order to reduce pollutants from the exhaust gas stream.
The three-way catalytic converter burns three types of exhaust gases:
| • | Carbon monoxide (CO) |
| • | Hydrocarbons (HC) |
| • | Oxides of nitrogen (NOx) |
The oxidation catalytic converter burns the same gases, but uses an air pump/smog pump to force added oxygen into the catalytic converter. The additional oxygen forces the converter to run hotter and to burn exhaust gases more effectively.
A single bed ceramic monolith style brick catalytic converter is used in combination with two types of catalyst
| • | Oxidation catalyst |
| • | Three-way (reduction/oxidation) catalyst |
The catalysts have coatings that contain platinum and palladium. These coatings burn the unwanted exhaust emissions.
Exhaust Muffler
The exhaust muffler is a tri-flow design.
| • | V6 engines without RPOs Y87 use a single outlet muffler. |
| • | V6 engines with RPO Y87 use a dual outlet muffler. |
The 5.7L (VIN G) engine uses the dual outlet muffler.
Hangers
Important: The installation of the exhaust system hangers is very important, as improperly installed hangers can cause annoying vibrations that can be difficult to diagnose.
The type of hanger used to support the exhaust system on this vehicle is a conventional rubber block. The rubber block is a rigid hanger with a feature that supports the exhaust system in case a rubber block is broken.
Clamps and Welded Connections
Caution: Exhaust may enter the vehicle and cause personal injury if the slip joints are not coated with exhaust system sealer before assembly.
There are no welded connections on this exhaust system. There is one slip joint that joins the catalytic converter to the muffler. One clamp connects the exhaust system slip joint.
The type of clamp used to connect the exhaust system slip joint is a single nut compression clamp.
On-Vehicle Service and Component Replacement
Exhaust system service includes the replacement of the following items:
| • | The catalytic converter |
| • | The catalytic converter and the exhaust muffler hangers |
| • | The complete exhaust system |
| • | The exhaust heat shield |
| • | The exhaust muffler |
Exhaust System Clearance Dimensions
Make all checking dimensions on a cold exhaust system.
If the specified dimensions cannot be met, there is a quality deficiency in a component. Correct the deficiency.
