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For 1990-2009 cars only

Heated Oxygen Sensor Replacement - Sensor 1 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 degrees C (120 degrees F).


    Object Number: 1889684  Size: SH
  1. Remove the connector position assurance (CPA) retainer.
  2. Disconnect the engine wiring harness electrical connector (5) from the HO2S electrical connector (4).
  3. Remove the HO2S connector clip (3) from the thermostat housing tab.

  4. Object Number: 1889759  Size: SH
  5. Remove the HO2S (2), if necessary use the J 39194-C .

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


    Object Number: 1889684  Size: SH
  5. Install the HO2S connector clip (3) to the thermostat housing tab.
  6. Connect the engine wiring harness electrical connector (5) to the HO2S electrical connector (4).
  7. Install the CPA retainer.