GM Service Manual Online
For 1990-2009 cars only

Special Tools

EN-48259 Oxygen Sensor Remover/Installer

Removal Procedure

    Warning: Refer to Battery Disconnect Warning in the Preface section.


    Object Number: 2042535  Size: SH
  1. Disconnect the battery negative cable. Refer to Battery Negative Cable Disconnection and Connection.
  2. Caution: Refer to Heated Oxygen and Oxygen Sensor Caution in the Preface section.

  3. Disconnect the electrical connector.
  4. Caution: Refer to Heated Oxygen and Oxygen Sensor Caution in the Preface section.

  5. Carefully remove the HO2S2 (1) by using the EN-48259 .

Installation Procedure


    Object Number: 2042535  Size: SH

    Note: A special anti-seize compound is used on the oxygen sensor threads. This compound consists of a liquid graphite 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 any engine and if for any reason it is to be reinstalled, the threads must have anti-seize compound applied before reinstallation.

  1. Coat the threads of the HO2S2 with an anti-seize compound, if needed.
  2. Caution: Refer to Fastener Caution in the Preface section.

  3. Install the HO2S2 (1) into the exhaust front pipe and tighten the oxygen sensor to 42 N·m (31 lb ft).
  4. Connect the HO2S2 connector.
  5. Connect the battery negative cable. Refer to Battery Negative Cable Disconnection and Connection.