1. Remove the powertrain. Refer to Powertrain Removal and Installation.



2. Remove the bolt (1) securing the catalytic converter pipe to the bell housing.
3. Remove the connector position assurance (CPA) lock for the oxygen sensor.



4. Disconnect the oxygen sensor electrical connectors (1, 2).

Caution: Refer to Oxygen Sensor Caution in the Preface section.

5. Remove the oxygen sensors.



6. Remove the right exhaust manifold heat shield bolts (2).
7. Remove the right exhaust manifold heat shield (1).



8. Remove the exhaust manifold bolts and nuts (2).
9. Remove the exhaust manifold, and old gasket. Discard the gasket.

Note: Tighten the exhaust manifold bolts as specified in the service procedure. Improperly installed and/or leaking exhaust manifold gaskets may effect vehicle emissions and/or On-Board Diagnostics (OBD) II system performance.

1. 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 and studs.



2. Position the exhaust manifold and a NEW gasket into place.

Caution: Refer to Fastener Caution in the Preface section.




3. Install the exhaust manifold bolts and nuts and tighten to 25 N·m (18 lb ft). Tighten the exhaust manifold bolts and nuts beginning with the center two nuts. Alternate from side-to-side, working toward the outside bolts and nuts.



4. Install the exhaust manifold and catalytic converter bolt (1) securing the pipe to the bell housing and tighten the exhaust hanger bolt to 50 N·m (37 lb ft).



5. Install the right exhaust manifold heat shield and bolts and tighten to 10 N·m (89 lb in).
6. Apply anti-sieze compound GM P/N 12377953 or equivalent to the threads of the oxygen sensors.

Caution: Refer to Oxygen Sensor Caution in the Preface section.

7. Install the oxygen sensors and tighten to 42 N·m (30 lb ft).



8. Connect the oxygen sensor electrical connectors (1).
9. Install the CPA locks (2).
10. Install the powertrain. Refer to Powertrain Removal and Installation.