Installation Procedure
NOTE:
- Tighten the exhaust manifold bolts as specified in the service procedure. Improperly installed and/or leaking exhaust manifold gaskets may affect vehicle emissions and/or On-Board Diagnostics (OBD) II system performance.
- The cylinder head exhaust manifold bolt hole threads must be clean and free of debris or threadlocking material.
- Do not apply sealant to the first 3 threads of the bolt.
- If the exhaust manifold was replaced, position and install the exhaust manifold heat shield, and bolts to the exhaust manifold.
Tighten
Tighten the bolts to 9 N.m (80 lb in).
- Clean the threads of the exhaust manifold bolts.
- Apply a 5 mm (0.2 in) wide band of threadlock GM P/N 12345493 (Canadian P/N 10953488), or equivalent to the threads of the exhaust manifold bolts.
- Install a NEW catalytic converter seal to the exhaust manifold.
- Position the NEW exhaust manifold gasket and exhaust manifold to the cylinder head.
- Ensure that the catalytic converter seal is seated to the catalytic converter.
- Install the exhaust manifold bolts.
Tighten
- Tighten the bolts a first pass to 15 N.m (11 lb ft). Tighten the exhaust manifold bolts beginning with the center 2 bolts. Alternate from side-to-side, and work toward the outside bolts.
- Tighten the bolts a final pass to 20 N.m (15 lb ft). Tighten the exhaust manifold bolts beginning with the center 2 bolts. Alternate from side-to-side, and work toward the outside bolts.
- Using a flat punch, bend the gasket tab at the rear of the gasket around the cylinder head edge.
- Install the oil level indicator tube to the engine block. Refer to Oil Level Indicator Tube Replacement .
- Install the spark plug wires (1) to the spark plugs.
- Install the spark plug wires to the ignition coils.
- Inspect the spark plug wires for proper installation.
- Push sideways on each boot in order to inspect the seating.
- Reinstall any loose boot.
- Fully raise and support the vehicle.
- Install the catalytic converter to exhaust manifold nuts. (1500 series shown, 2500 series similar).
Tighten
Tighten the nuts to 50 N.m (37 lb ft).
- Partially lower the vehicle in order to work through the wheel opening.
- Install the front wheel house liner - right front. Refer to Front Wheelhouse Liner Replacement - Right Side .
- Install the HO2S. Refer to Heated Oxygen Sensor Replacement - Bank 2 Sensor 1 (1500 Series) , Heated Oxygen Sensor Replacement - Bank 2 Sensor 1 (2500 Series) .
- Inspect the exhaust system for leaks.
CAUTION:
Refer to Fastener Caution .