Oxygen Sensor: Service and Repair

REMOVAL

NOTE: Do not apply excessive force to sensor when removing, especially when engine is cold. Permanent damage to the exhaust pipe may result.

1. Disconnect oxygen sensor electrical connector.
2. Apply a penetrating oil to the sensor base and allow to stand for one minute.
3. Loosen sensor 10° to 40° with a suitable tool (Subaru #499990110).
4. Again, apply a penetrating oil to the sensor base and allow to stand for one minute.
5. Remove sensor from vehicle.


INSTALLATION
1. Being careful to protect the sensor tip, apply a suitable high-temp anti-seize compound to the threaded portion of the oxygen sensor.
2. Thread sensor into exhaust pipe by hand as far as it will go.
3. Using a suitable socket, torque sensor to 18 - 25 ft.lbs (25 - 34 Nm).
4. Reconnect and secure oxygen sensor electrical connector.