Exhaust Manifold Replacement - Left Side LZ4

Tools Required

J 39194-B Heated Oxygen Sensor Wrench

1. Remove the air cleaner outlet duct. Refer to Air Cleaner Outlet Duct Replacement .
2. Remove the connector position assurance (CPA) retainer (2).
3. Disconnect the heated oxygen sensor (HO2S) electrical connector (1).

Important: The HO2S uses a permanently attached pigtail and connector. This pigtail should not be removed from the sensor. Damage or removal of the pigtail or connector will affect proper operation of the sensor.

4. Remove the HO2S using the J 39194-B .



5. Remove the exhaust manifold heat shield bolts and shield.



6. Remove the upper exhaust manifold nuts.
7. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle .
8. Remove the left catalytic converter. Refer to Catalytic Converter Replacement - Left Side .
9. Remove the lower exhaust manifold nuts.
10. Remove the exhaust manifold.
11. Remove and discard the exhaust manifold gasket.

1. Install a NEW exhaust manifold gasket onto the cylinder head studs.
2. Install the exhaust manifold.

Notice: Refer to Fastener Notice in the Preface section.

3. Install the exhaust manifold nuts.

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

4. Install the left catalytic converter. Refer to Catalytic Converter Replacement - Left Side .



5. Install the exhaust manifold heat shield and bolts.

Tighten
Tighten the bolts to 10 N·m (89 lb in).





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

6. Install the HO2S using J 39194-B .

Tighten
Tighten the sensor to 42 N·m (31 lb ft).

7. Connect the HO2S electrical connector (1).
8. Install the CPA retainer (2).
9. Ensure that the connector rosebud is attached to the clip.
10. Install the air cleaner outlet duct. Refer to Air Cleaner Outlet Duct Replacement .

Exhaust Manifold Replacement - Left Side LY7

Caution: Refer to Exhaust Service Caution in the Preface section.

Caution: Refer to Protective Goggles and Glove Caution in the Preface section.

1. Remove the exhaust manifold heat shield. Refer to Exhaust Manifold Heat Shield Replacement - Left Side .
2. Remove the oil level indicator. Refer to Oil Level Indicator and Tube Replacement .
3. Remove the catalytic converter to exhaust manifold nuts (1).



4. Remove the exhaust manifold bolts (1).
5. Remove the exhaust manifold and gasket. Discard the gasket.

1. Install one exhaust manifold bolt to the exhaust manifold.
2. Install the NEW exhaust manifold gasket onto the cylinder head and bolt.
3. Install the exhaust manifold (with gasket) to the catalytic converter and the cylinder head.

Notice: Refer to Fastener Notice in the Preface section.

4. Install the remaining exhaust manifold bolts (1).

Tighten
Tighten the bolts to 20 N·m (15 lb ft).




5. Install the catalytic converter to exhaust manifold nuts (1).

Tighten
Tighten the nuts to 45 N·m (33 lb ft).

6. Install the oil level indicator. Refer to Oil Level Indicator and Tube Replacement .
7. Install the exhaust manifold heat shield. Refer to Exhaust Manifold Heat Shield Replacement - Left Side .
8. Inspect for exhaust leaks.