An intermediate or center pipe runs from the catalytic converter to the muffler at the rear of the vehicle. Depending on the engine in the vehicle, this pipe may contain a resonator or pre-muffler which serves to quiet and smooth out the exhaust flow before it enters the rear muffler. The resonator is welded into the pipe and is not removable.
The muffler, with its entry pipe and tail pipe, complete the system and serve to further quiet and cool the exhaust. Mitsubishi mufflers have lead-in and exhaust pipes welded to the body of the muffler. If one of the pipes is damaged, the complete muffler assembly should be replaced.
The exhaust system is attached to the body by several welded hooks and flexible rubber hangers; these hangers absorb exhaust vibrations and isolate the system from the body of the car. A series of metal heat shields runs along the exhaust piping, protecting the underbody from excess heat. These heat shields should be the first place to look when chasing a light metallic rattle or buzz under the vehicle. Because the shields are exposed under the body work, they may become bent, loose or packed with road debris.
When inspecting or replacing exhaust system parts, make sure there is adequate clearance from all points on the body to avoid possible overheating of the floor pan. Check the complete system for broken, damaged, missing or poorly positioned parts. Rattles and vibrations in the exhaust system may be caused by misalignment of parts. When aligning the system, leave all the nuts and bolts loose until everything is in its proper place, then tighten the hardware working from the front to the rear. Remember that what appears to be proper clearance during repair may change as the vehicle moves down the road. The motion of the engine, body and suspension must be considered when replacing parts.
For exhaust component removal and installation, a good rule of thumb is to disconnect the forward-most joint first, then the rear joint, then remove the component from its hangers. This is particularly important when working with the front pipe or the complete system; if the weight of the pipe(s) is allowed to rest on the ground, the length of the system can develop enough leverage to break or damage the manifold or turbocharger.
In general, if any component is attached at both ends, it's easier to remove the entire system from the vehicle and do the repair where you can see it. Remember to use new gaskets at every disassembled joint.
When disassembling the rubber and/or metal hangers, take close note of the style and location of each, labeling or diagraming them if necessary to insure correct reinstallation. The manufacturer selects the hangers and bushings to deliver the maximum support and isolation. If any of the hangers or hardware look to be in poor condition, replace the piece.