GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

    Caution: Refer to Heated Oxygen and Oxygen Sensor Caution in the Preface section.


    Object Number: 1876457  Size: SH
  1. Raise and suitably support the vehicle. Refer to Lifting and Jacking the Vehicle.
  2. Remove the connector position assurance (CPA) retainer.
  3. Disconnect the engine wiring harness electrical connector (2) from the HO2S pigtail electrical connector (1).
  4. Remove the HO2S pigtail electrical connector clip from the engine wiring harness clip (3).

  5. Object Number: 1876458  Size: SH
  6. Remove the HO2S (3).

Installation Procedure


    Object Number: 1876458  Size: SH

    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 glass beads remain, making the sensor easier to 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 old sensor is to be reinstalled, the threads must have anti-seize compound applied before the reinstallation.

  1. If reinstalling the old HO2S, coat the threads with anti-seize compound GM P/N 12377953, or equivalent.
  2. Caution: Refer to Fastener Caution in the Preface section.

  3. Install the HO2S (3).
  4. Tighten
    Tighten the sensor to 42 N·m (31 lb ft).


    Object Number: 1876457  Size: SH
  5. Install the HO2S pigtail electrical connector clip to the engine wiring harness clip (3).
  6. Connect the engine wiring harness electrical connector (2) to the HO2S pigtail electrical connector (1).
  7. Install the CPA retainer.
  8. Lower the vehicle.