Upstream Heated Oxygen Sensor Replacement

HO2S 1/1:

HO2S 2/1:

This engine uses two upstream heated oxygen sensors. One oxygen sensor is threaded into the outlet flange of each exhaust manifold.

WARNING: THE EXHAUST MANIFOLD, EXHAUST PIPES AND CATALYTIC CONVERTER BECOME VERY HOT DURING ENGINE OPERATION. ALLOW ENGINE TO COOL BEFORE REMOVING OXYGEN SENSOR.

REMOVAL

CAUTION: When disconnecting the sensor electrical connector, do not pull directly on wire going into sensor.

1. Remove the negative battery cable.
2. Disconnect the heated oxygen sensor electrical connector.
3. Use a socket such as Snap-On YA8875 or a crow's foot wrench to remove oxygen sensor.

INSTALLATION
1. After removing the sensor, the exhaust manifold threads must be cleaned with an 18 mm X 1.5 + 6E tap. If reusing the original sensor, coat the sensor threads with an anti-seize compound such as Loctite 771-64 or equivalent. New sensors have compound on the threads and do not require an additional coating. Tighten the sensor to 28 Nm (20 ft. lbs.) torque.
2. Connect the heated oxygen sensor electrical connector.
3. Install the negative battery cable.