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For 1990-2009 cars only

Heated Oxygen Sensor Replacement - Sensor 2 LAT and LE5

Special Tools

J 39194-C Oxygen Sensor Wrench

Removal Procedure

Caution: 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.

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

Note: 

   • 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: 1889758  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 HO2S electrical connector (2) from the engine wiring harness electrical connector (1).

  4. Object Number: 1889759  Size: SH
  5. Remove the HO2S (1), if necessary use the J 39194 .

Installation Procedure

Note: 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: 1889759  Size: SH
  1. If necessary, coat the threads of the HO2S with anti-seize compound GM P/N 12377953 or equivalent.
  2. Caution: Refer to Fastener Caution in the Preface section.

  3. Install the HO2S (1), if necessary use the J 39194-C .
  4. Tighten
    Tighten the sensor to 42 N·m (31 lb ft).


    Object Number: 1889758  Size: SH
  5. Connect the HO2S electrical connector (2) to the engine wiring harness electrical connector (1).
  6. Install the CPA retainer.
  7. Lower the vehicle.