Installation Procedure
WARNING: This page is about a different car, the 2004 GMC Sierra, 2004 GMC Cab & Chassis Sierra, 2004 Chevrolet Silverado, and 2004 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
Refer to Fastener Notice in Cautions and Notices.
- If the catalytic converter was replaced, perform the following:
- Apply anti-seize compound GM P/N 12377953 or equivalent to the threads of the old oxygen sensors.
- Install the oxygen sensors.
Tighten: Tighten the sensors to 42 N.m (31 lb ft).
- If equipped with a 6.0L engine, with RPO Y91, install a NEW exhaust seal to the exhaust manifold.
- Install the catalytic converter.
Slide the catalytic converter hanger into the exhaust pipe hanger bracket.
- Install a NEW exhaust seal to the exhaust manifold.
- Install the catalytic converter.
Slide the catalytic converter hanger into the exhaust pipe hanger bracket.
- Install the left exhaust manifold pipe nuts.
- Tighten the right exhaust manifold pipe nuts.
Tighten: Tighten the nuts to 50 N.m (39 lb ft).
- Using the transmission jack, raise the transmission slightly.
- Connect the oxygen sensor electrical connectors (1, 2).
- Connect the CPA retainers.
- Install the muffler. Refer to Muffler Replacement (4.3L, 4.8L, and 5.3L Engines) or Muffler Replacement (6.0L, 6.6L, and 8.1L Engines) .
- Install the transmission support crossmember.
- Install the transmission support crossmember bolts.
Tighten: Tighten the bolts to 95 N.m (70 lb ft).
- Lower the transmission onto the transmission support.
- Install the transmission mount to transmission support nuts.
Tighten: Tighten the nuts to 40 N.m (30 lb ft).
- Remove the support from the transmission.
- Lower the vehicle.