Sierra Classic 2500 4WD V8-8.1L (2007)
19. Remove the oxygen sensors if the catalytic converter is to be replaced.
Installation Procedure
Notice: Refer to Fastener Notice in Service Precautions.
1. If the catalytic converter was replaced, perform the following:
1. Apply anti-seize compound GM P/N 12377953 or equivalent to the threads of the old oxygen sensors.
2. Install the oxygen sensors.
Tighten the sensors to 42 Nm (31 ft. lbs.).
2. If equipped with a 6.0L engine, with RPO Y91, install a NEW exhaust seal to the exhaust manifold.
3. Install the catalytic converter. Slide the catalytic converter hanger into the exhaust pipe hanger bracket.
4. Install a NEW exhaust seal to the exhaust manifold.