Oxygen Sensor: Service and Repair

NOTE: The Heated Oxygen Sensor (HO2S) and the Oxygen Sensor use a permanently attached pigtail and connector. Do not remove this pigtail from the Heated Oxygen Sensor. Damage or the removal of the pigtail or the connector could affect the proper operation of the sensor.

Take care when handling the HO2S and the O2S. Keep the in-line electrical connector and the louvered end free of grease, dirt, or other contaminants. Also avoid using cleaning solvents of any type. Do not drop the HO2S or the O2S. Do not roughly handle the HO2S or the O2S.

REMOVAL PROCEDURE

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




1. Turn the ignition OFF.
2. If the HO2S 1 is being replaced, remove the fuel injector sight shield. Refer to Fuel injector Sight Shield Replacement (L36) or Fuel injector Sight Shield Replacement (L67) in Engine Mechanical.
3. If the HO2S 2 is being replaced, raise the vehicle. Refer to Lifting and Jacking the Vehicle in General information.




4. Disconnect the electrical connector.
5. Carefully back out the heated oxygen sensor.

INSTALLATION PROCEDURE

IMPORTANT: A special anti-seize compound is used on the heated oxygen sensor 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 if for any reason is to be reinstalled, the threads must have anti-seize compound applied before reinstallation.




1. If necessary, coat the threads of the heated oxygen sensor/catalyst monitor with anti-seize compound P/N 5613695, or equivalent.

NOTE: Refer to Fastener Notice in Service Precautions.




2. Install the heated oxygen sensor.

Tighten
Tighten the heated oxygen sensor to 41 N.m (30 lb ft).

3. Connect the electrical connector.
4. Lower the vehicle.
5. If the HO2S 1 is being replaced, install the fuel injector sight shield. Refer to Fuel injector Sight Shield Replacement (L36) or Fuel injector Sight Shield Replacement (L67) in Engine Mechanical.