Sierra 3500 4WD V8-6.6L DSL Turbo VIN 2 (2004)
23. If equipped with a 6.6L engine, remove the insulators from the frame hangers.
24. With the aid of an assistant, slide the muffler rearward in order to remove the muffler from the exhaust muffler pipe.
25. Remove the exhaust muffler gasket, if necessary.
26. Remove the insulators from the muffler hangers.
27. If equipped with a 6.0L or 8.1L engine, remove the oxygen sensor if the muffler is being replaced.
28. If the muffler is NOT being replaced as an assembly, the band clamp MUST be replaced. Perform the following:
0. Mark the position of the band clamp on the intermediate exhaust pipe.
1. Remove the band clamp from the exhaust pipe by grinding the weld.
2. Install a NEW band clamp onto the exhaust pipe.
Installation Procedure
1. If equipped with a 6.0L or 8.1L engine, and the muffler was replaced re-install the old oxygen sensor.
2. Apply anti-seize compound GM P/N 12377953 or equivalent to the threads of the old oxygen sensor.
Notice: Refer to Fastener Notice in Service Precautions.
3. Install the oxygen sensor.
Tighten the sensor to 42 Nm (31 ft. lbs.).
