GM Service Manual Online
For 1990-2009 cars only

Special Tools

EN-46577 Oxygen Sensor Remover/Installer

Removal Procedure

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


    Object Number: 1241561  Size: SH
  1. Disconnect the negative battery cable.
  2. Caution: Refer to Heated Oxygen and Oxygen Sensor Caution in the Preface section.

  3. Disconnect the front heated oxygen sensor (HO2S1) connector.
  4. Caution: Remove oxygen sensors with the engine temperature above 48°C (120°F). Otherwise the oxygen sensors may be difficult to remove.

  5. Carefully remove the HO2S1 from the exhaust manifold using EN-46577 .

Installation Procedure


    Object Number: 1241561  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 HO2S1 will an anti-seize compound, if needed.
  2. Caution: Refer to Fastener Caution in the Preface section.

  3. Install the HO2S1 to the exhaust manifold using EN-46577 .
  4. Tighten
    Tighten the oxygen sensor to 42 N·m (31 lb ft).

  5. Connect the HO2S1 connector.
  6. Connect the negative battery cable.