Sierra Classic 1500 4WD V8-6.0L (2007)
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.
3. Notice: Refer to Fastener Notice in Service Precautions.
Install the oxygen sensor.
Tighten the sensor to 42 Nm (31 ft. lbs.).
4. If equipped with a 6.6L engine, using the aid of an assistant, align the muffler locator button (3) to the catalytic converter coupling groove (2).
5. Install the muffler until the locator button is fully engaged by the coupling clip (1).
6. Important: Apply lubricant to the insulators to aid in installation.
If equipped with a 6.6L engine, install the insulators to the muffler hangers.
7. Install a new exhaust muffler gasket.