Removal Procedure

NOTE: Refer to Oxygen Sensor Notice in Cautions and Notices.

NOTE: Refer to Heated Oxygen Sensor (HO2S) Resistance Learn Reset Notice in Cautions and Notices.

IMPORTANT:

Remove oxygen sensors with the engine temperature above 48°C (120°F). Otherwise the oxygen sensors may be difficult to remove.
A special anti-seize compound is used on the oxygen sensor threads. New service sensors should already have the compound applied to the threads. Coat the threads of a reused sensor with anti-seize compound P/N 5613695 or equivalent.

Fig 1: View of Rear Oxygen Sensor

Courtesy of GENERAL MOTORS CORP.

Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
Support rear of the powertrain frame.
Remove four rear frame bolts.
Lower the frame no more than 73.2 mm (3 inches).
Disconnect the rear oxygen sensor electrical connector.
Remove the rear oxygen sensor from the rear exhaust manifold.