Removal Procedure

Remove the fuel injection sight shield. Refer to Fuel Injector Sight Shield Replacement (L36) in Engine Mechanical.
Turn OFF the ignition switch.
Remove the HO2S retaining clip from the bracket.
Disconnect the HO2S electrical connector tab from the HO2S 1 retaining clip.
Remove the HO2S electrical connector retainer.
Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.

Fig 1: Removing Heated Oxygen Sensor From Rear Exhaust Manifold

Courtesy of GENERAL MOTORS CORP.

IMPORTANT: Remove oxygen sensors with the engine temperature above 48°C (120°F). Otherwise the oxygen sensors may be difficult to remove.

Remove the rear oxygen sensor (2) from the rear exhaust manifold carefully using the J 39194 . See Special Tools .