Downstream O2 Sensor

The O2S are located at the outlet ends of the catalytic converter.

REMOVAL

O2 Sensor 2.7L:

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

1. Remove the negative battery cable. (2) Raise and support the vehicle.
3. Disconnect the wire connector from the O2S.

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

4. Remove the O2S. Snap-On oxygen sensor wrench (number YA 8875) may be used for removal and installation.

INSTALLATION
1. After removing the sensor, the exhaust manifold threads must be cleaned with an 18 mm X 1.5 + 6 E 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 N.m (20 ft. lbs.) torque.
2. Install the O2S. Tighten to 28 N.m (20 ft. lbs.) torque.
3. Connect the O2S wire connector.
4. Lower the vehicle.
5. Install the negative battery cable.