Oxygen Sensor: Testing and Inspection

Heated oxygen sensor (front)
1. Disconnect the heated oxygen sensor connector.




2. Check that there is continuity between terminal 3 and terminal 4 on the heated oxygen sensor connector.
3. If there is no continuity, replace the heated oxygen sensor.
4. Warm up the engine until engine coolant is 80° (176°F) or higher.
5. Use the jumper wires to connect terminal 3 of the heated oxygen sensor connector to the battery (+) terminal and terminal 4 to the battery (-) terminal.

CAUTION: Be very careful when connecting the jumper wires, or the heated oxygen sensor can be damaged.




6. Connect a digital voltmeter between terminal 1 and terminal 2.
7. While repeatedly racing the engine, measure the heated oxygen sensor output voltage.




8. If the sensor is defective, replace the heated oxygen sensor.

NOTE: For removal and installation of the heated oxygen sensor, refer to Exhaust Pipe, Main Muffler.




Heated oxygen sensor (rear)
1. Disconnect the heated oxygen sensor connector.
2. Check that there is continuity between terminal 1 and terminal 2 on the heated oxygen sensor connector.
3. If there is no continuity, replace the heated oxygen sensor.

NOTE
1. If the scan tool does not display the standard value although no malfunction is found by the above-mentioned continuity test and harness check, replace the heated oxygen sensor (rear).
2. For removal and installation of the oxygen sensor, refer to Exhaust Pipe, Main Muffler.