Oxygen Sensor: Service and Repair

REMOVAL
1. Disconnect the negative battery cable.
2. Locate the two oxygen sensors.




- Bank 1 sensor 1 is mounted on the exhaust pipe ahead of the catalytic converter.




- Bank 1 sensor 2 is mounted behind the catalytic converter.




3. Disconnect the pigtail from the wiring harness.

NOTE: The pigtail is permanently attached to the sensor. Be careful not to pull the wires out.

CAUTION: Do not use a torch to remove a Heated Oxygen Sensor (HO2S) unless the sensor is being replaced. Using a torch could damage the sensor.

4. Remove the sensor from the exhaust pipe.
- Because of the expansion and contraction of the metal in the exhaust system over time, this may be difficult if the engine temperature is below 48°C (120°F).

INSPECTION
Both sensors are identical. Inspect each in the same way.

1. Inspect the pigtail and the electrical connector for grease, dirt, corrosion, and bare wires or worn insulation.
2. Inspect the louvered end of the sensor for grease, dirt, or other contaminants.




INSTALLATION

NOTE:
- A special anti-seize compound, P/N 5613695, is used on the HO2S threads. This compound consists of glass beads suspended in a liquid graphite solution. The graphite burns away with engine heat, 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 and is to be reinstalled for any reason, the threads must have anti-seize compound applied.

1. Apply anti-seize compound or the equivalent to the threads of the oxygen sensor, if necessary.
2. Install the oxygen sensor on the exhaust pipe in its original position.
- Tighten the oxygen sensor to 55 N.m (40 lb ft).

3. Connect the pigtail to the wiring harness.
4. Connect the negative battery cable.