Exhaust Pipe: Service and Repair

Exhaust Manifold Pipe Replacement (L61)

Tools Required

J 39194 Oxygen Sensor Wrench


Removal Procedure

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


Important: 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 HO2S.



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







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





Notice: 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.



Installation Procedure





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.

Notice: Refer to Fastener Notice (Fastener Notice) .

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

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





5. Install the exhaust manifold pipe to muffler nuts.

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






Important: 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. 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 the sensor to 42 N.m (30 lb ft).





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