Tools Required

J 39194-B Heated Oxygen Sensor Socket

1. Remove the accessory drive belt. Refer to Drive Belt Replacement in Engine Mechanical.



2. Remove the generator. Refer to Generator Replacement in Engine Electrical.



3. Disconnect the rear heated oxygen sensor (HO2S) connector.
4. Remove the rear HO2S using J 39194-B .



5. Remove the exhaust manifold heat shield.



6. Remove the exhaust gas recirculation (EGR) pipe.



7. Remove the upper exhaust manifold to cylinder head nuts.
8. Remove the upward-pointing fastener from the rear catalyst assembly.
9. Raise the vehicle.
10. Remove the crossover pipe . Refer to Exhaust Crossover Pipe Replacement .
11. Remove the rear catalyst assembly. Refer to Catalytic Converter Replacement .



12. Remove the exhaust manifold nuts.
13. Remove the exhaust manifold assembly.
14. Remove the exhaust manifold gasket.

1. Install a new manifold gasket on the cylinder head.
2. Install the exhaust manifold.

Notice: Refer to Fastener Notice in the Preface section.

3. Install the exhaust manifold nuts.

Tighten
Tighten the exhaust manifold nuts to 16 N·m (12 lb ft).

4. Install the rear catalyst assembly and gasket. Refer to Catalytic Converter Replacement .
5. Install the crossover pipe and gaskets. Refer to Exhaust Crossover Pipe Replacement .



6. Install the EGR pipe.

Tighten
Tighten the EGR pipe bolts to 25 N·m (18 lb ft).




7. Install the exhaust manifold heat shield.

Tighten
Tighten the exhaust manifold heat shield bolts to 18 N·m (12 lb ft).





Important: Whenever the oxygen sensor is removed, coat the threads with nickel-based anti-seize compound such as GM P/N 5613695 (or equivalent).

8. Install the HO2S into the exhaust manifold using J 39194-B .

Tighten
Tighten the oxygen sensor-to-exhaust manifold pipe to 41 N·m (30 lb ft).

9. Connect the HO2S electrical connector. Assure the connector and wiring are fully retained away from the exhaust manifold and heat shield edges.



10. Install the generator. Refer to Generator Replacement in Engine Electrical.