87. Exhaust Manifold Installation - Left

IMPORTANT: 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 Diagnostic (OBD) 11 system performance. The cylinder head exhaust manifold bolt hole threads must be clean and free of debris or threadlocking material.

IMPORTANT: Do not apply sealant to the first three threads of the bolt.





1. Apply a 5 mm (0.20 inch) wide band of threadlock GM P/N 12345493 or equivalent to the threads of the exhaust manifold bolts.
2. Install the exhaust manifold and NEW exhaust manifold gasket.

NOTICE: Refer to Fastener Notice in Service Precautions.

3. Install the exhaust manifold bolts.
3.1. Tighten the exhaust manifold bolts a first pass to 15 Nm (11 lb ft). Tighten the exhaust manifold bolts beginning with the center two bolts. Alternate from side-to-side, and work toward the outside bolts.
3.2. Tighten the exhaust manifold bolts a final pass to 25 Nm (18 ft. lbs). Tighten the exhaust manifold bolts beginning with the center two bolts. Alternate from side-to-side, and work toward the outside bolts.
4. Using a flat punch, bend over the exposed edge of the exhaust manifold gasket at the rear of the left cylinder head.





5. Install the heat shield (2) and bolts (3).
^ Tighten the heat shield bolts to 9 Nm (80 lb in).





6. Install the Air Injection Reaction (AIR) pipe studs (if required).
^ Tighten the studs to 5 Nm (45 lb in).
7. Install the AIR pipe (with check valve), NEW gasket and nuts (if required).
^ Tighten the AIR pipe to exhaust manifold nuts to 25 Nm (18 ft. lbs).