GM Service Manual Online
For 1990-2009 cars only

The exhaust system is supported by free-hanging rubber mounts which permit some movement of the exhaust system. The rubber mounts also inhibit the transfer of noise or vibration into the passenger compartment.

The transfer of rattles and noise vibrations in the exhaust system can be caused by misalignment of parts or retention of heat shields. When aligning the exhaust system, leave all the bolts or nuts loose until the parts are properly aligned, then tighten the bolts and nuts working from the front to the rear of the vehicle.