Exhaust Manifold Replacement - Right Side LY7

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

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




1. Remove the catalytic converter. Refer to Catalytic Converter Replacement - Right Side.
2. Remove the exhaust manifold lower bolts.
3. Lower the vehicle half way.



4. Remove the exhaust manifold upper bolts.



5. Remove the exhaust manifold.



6. Remove and discard the exhaust manifold gasket.

1. Install one upper exhaust manifold bolt (1) to the exhaust manifold.
2. Place the NEW exhaust manifold gasket onto the bolt.
3. Position and install the exhaust manifold (with gasket) to the cylinder head.



4. Loosely install the remaining upper exhaust manifold bolts.
5. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle.



6. Loosely install the lower exhaust manifold bolts.

Caution: Refer to Fastener Caution in the Preface section.

7. Tighten the exhaust manifold bolts to 20 N·m (15 lb ft).
8. Install the catalytic converter. Refer to Catalytic Converter Replacement - Right Side.

Exhaust Manifold Replacement - Right Side LZ4

Special Tools

J 39194-B Heated Oxygen Sensor Socket

Caution: The oxygen sensor uses a permanently attached pigtail and connector. Do not remove the pigtail from the oxygen sensor. Damage to or removal of the pigtail connector could affect proper operation of the oxygen sensor.

Caution: The use of excessive force may damage the threads in the exhaust manifold/pipe.

Note: The in-line connector and louvered end must be kept clear of grease, dirt or other contaminants. Avoid using cleaning solvents of any type. DO NOT drop or roughly handle the heated oxygen sensor (HO2S).

Note: The HO2S may be difficult to remove when the engine temperature is less than 48°C (120°F)

1. Remove the generator. Refer to Generator Replacement.
2. Remove the connector position assurance (CPA) retainer (3).
3. Disconnect the engine wiring harness electrical connector (2) from the HO2S electrical connector.
4. Remove the HO2S electrical connector rosebud clip (1) from the ignition coil bracket.



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



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



7. Remove the upper exhaust manifold bolts.
8. Remove the right catalytic converter. Refer to Catalytic Converter Replacement - Right Side.
9. Remove the lower exhaust manifold bolts.
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.

Caution: Refer to Fastener Caution in the Preface section.

3. Install the exhaust manifold bolts and tighten to 20 N·m (15 lb ft).
4. Install the right catalytic converter. Refer to Catalytic Converter Replacement - Right Side.



5. Install the exhaust manifold heat shield and bolts. Tighten the bolts to 10 N·m (89 lb in).




Note: A special anti-seize compound is used on the HO2S threads. The compound consists of graphite suspended in fluid and glass beads. The graphite will burn away, but the glass beads will remain, making the sensor easier to remove. New or service sensors will already have the compound applied to the threads. If a sensor is removed from an engine and is to be reinstalled, the threads must have anti-seize compound applied before the reinstallation.

6. Coat the threads of the HO2S with anti-seize compound GM P/N 12377953 or equivalent, if necessary.
7. Install the HO2S using J 39194-B . Tighten the sensor to 42 N·m (31 lb ft).



8. Connect the engine wiring harness electrical connector (2) to the HO2S electrical connector.
9. Install the CPA retainer (3).
10. Install the HO2S electrical connector rosebud clip (1) to the ignition coil bracket.
11. Install the generator. Refer to Generator Replacement.