Exhaust Manifold Pipe Replacement LE5

Special Tools

J 39194 Oxygen Sensor Wrench

1. Raise and support the vehicle. Refer Lifting and Jacking the Vehicle.
2. Remove the connector position assurance (CPA) retainer (1).
3. Disconnect the heated oxygen sensor (HO2S) electrical connector (2).




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.

4. Using the J 39194 , remove the HO2S.



5. Remove the exhaust manifold pipe to muffler nuts.



6. Remove the exhaust manifold/catalytic converter to exhaust manifold pipe nuts.
7. Remove the first muffler hanger insulator.
8. Gently pull back and separate the muffler from the exhaust manifold pipe studs.
9. Remove the exhaust manifold pipe.

1. Install the exhaust manifold pipe to the exhaust manifold/catalytic converter.
2. Gently pull back and install the exhaust manifold pipe studs to the muffler.
3. Install the first muffler hanger insulator.

Caution: Refer to Fastener Caution in the Preface section.

4. Install the exhaust manifold/catalytic converter to exhaust manifold pipe nuts.

Tighten
Tighten the nuts to 35 N·m (26 lb ft).




5. Install the exhaust manifold pipe to muffler nuts.

Tighten
Tighten the nuts to 30 N·m (22 lb ft).





Note: A special anti-seize compound is used on the HO2S threads. The compound consists of liquid graphite and glass beads. The graphite tends to burn away but the beads remain, making the sensor easier the remove. New, or service replacement sensors already have the compound applied to the threads. If the sensor is removed from an exhaust component and if for any reason the sensor is to be reinstalled, the threads must be have anti-seize compound applied before the reinstallation.

6. If reinstalling the old HO2S, coat the threads with anti-seize compound GM P/N 12377953 or equivalent.
7. Using the J 39194 , install the HO2S.

Tighten
Tighten the HO2S to 41 N·m (30 lb ft).




8. Connect the HO2S electrical connector (2).
9. Install the CPA retainer (1).
10. Lower the vehicle.