Exhaust System: Description and Operation

Exhaust System

COMPONENT LOCATION









INTRODUCTION
The 4.2L V8 exhaust system is fabricated from stainless steel and is supplied as four separate assemblies:
- A LH front section incorporating a catalytic converter
- A RH front section incorporating a catalytic converter
- A center section incorporating a silencer
- A rear section Including the main silencer box.
Each section of the exhaust system is available as a service replacement.
The exhaust system is attached to the underside of the body with five mounting rubbers, two on the center section and three on the rear muffler. The mounting rubbers attach to the exhaust system via stainless steel hangers and brackets. The mounting rubbers locate on corresponding hangers which are attached to the underside of the vehicle body. The system is routed along the center of the chassis before splitting near the rear differential prior to entering the main exhaust silencer at the rear of the vehicle.
To reduce the carbon monoxide and hydrocarbons content of the exhaust gases, a catalytic converter is integrated into each of the front pipes of the exhaust system.
The rear muffler unit includes a Semi Active Muffler (SAM) valve. This valve is operated by the pressure in the exhaust system. At low engine speed the valve is partially closed to provide a more refined noise quality. At higher engine speed the increased pressure within the exhaust system opens the valve to provide a more sporting noise. The SAM valve is non serviceable and the rear muffler is replaced as a complete assembly.