GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 39194-C Oxygen Sensor Wrench

Removal Procedure

Notice: The oxygen sensor uses a permanently attached pigtail and connector. Do not remove the pigtail from the oxygen sensor. Damage to or removal of the pigtail connector could affect proper operation of the oxygen sensor.

Notice: The use of excessive force may damage the threads in the exhaust manifold/pipe.

Important: 

   • The in-line connector and louvered end must be kept clear of grease, dirt or other contaminants. Avoid using cleaning solvents of any type. DO NOT drop or roughly handle the heated oxygen sensor (HO2S).
   • The HO2S may be difficult to remove when the engine temperature is less than 48°C (120°F).


    Object Number: 1648166  Size: SH
  1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle .
  2. Remove the connector position assurance (CPA) retainer.
  3. Disconnect the HO2S electrical connector (4) from the engine wiring harness electrical connector (3).

  4. Object Number: 1814566  Size: SH
  5. Remove the HO2S wiring pigtail from the heat shield crimp.
  6. Remove the HO2S using the J 39194 .

Installation Procedure

Important: A special anti-seize compound is used on the heated oxygen sensor threads. The 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 replacement sensors will have the compound applied to the threads. If a sensor is removed and is to be reinstalled, the threads must have an anti-seize compound applied prior to installation.


    Object Number: 1814566  Size: SH
  1. If necessary, coat the threads of the HO2S with anti-seize compound Saturn P/N 21485279 or equivalent.
  2. Notice: Refer to Fastener Notice in the Preface section.

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

  5. Install the HO2S wiring pigtail to the heat shield crimp.

  6. Object Number: 1648166  Size: SH
  7. Connect the HO2S electrical connector (4) to the engine wiring harness electrical connector (3).
  8. Install the CPA retainer.
  9. Lower the vehicle.