GM Service Manual Online
For 1990-2009 cars only

Special Tools

J 39194-B Heated Oxygen Sensor Wrench

Removal Procedure

Caution: Refer to Heated Oxygen Sensor Resistance Learn Reset Caution in the Preface section.


    Object Number: 1774876  Size: SH
  1. Remove the connector position assurance (CPA) retainer (5).
  2. Disconnect the engine wiring harness electrical connector (4) from the heated oxygen sensor (HO2S) electrical connector (3).
  3. Remove the HO2S rosebud clip from the oil level indicator tube tab.

  4. Object Number: 1585918  Size: SH

    Caution: The oxygen sensor may be difficult to remove when the engine temperature is below 48°C (120°F). Excessive force may damage threads in the exhaust manifold or the exhaust pipe.

  5. Remove the HO2S using the J 39194-B .

Installation Procedure


    Object Number: 1585918  Size: SH

    Note : A special anti-seize compound is used on the HO2S 1 threads. The compound consists of graphite suspended in fluid 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 an engine and is to be reinstalled, the threads must have anti-seize compound applied before the reinstallation.

  1. Coat the threads of the HO2S with anti-seize compound GM P/N 12377953 or equivalent, if necessary.
  2. Caution: Refer to Fastener Caution in the Preface section.

  3. Install the HO2S.
  4. Tighten
    Tighten the sensor to 42 N·m (31 lb ft) using the J 39194-B .


    Object Number: 1774876  Size: SH
  5. Connect the engine wiring harness electrical connector (4) to the HO2S electrical connector (3).
  6. Install the CPA retainer (5).
  7. Install the HO2S rosebud clip to the oil level indicator tube tab.