Oxygen Sensor: Testing and Inspection
OXYGEN SENSOR TESTINGHeated oxygen sensor (front)
1. Disconnect the heated oxygen sensor connector and connect the special tool (test harness) to the connector on the heated oxygen sensor side.
2. Make sure that there is continuity [7-40 ohms at 20°C (68°F)]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°C (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; incorrect connection can damage the heated oxygen sensor.
6. Connect a digital voltage meter between terminal 1 and terminal 2.
7. While repeatedly racing the engine, measure the heated oxygen sensor output voltage.
Standard value
8. It the sensor is defective, replace the heated oxygen sensor.
Heated oxygen sensor (rear)
1. Disconnect the heated oxygen sensor connector.
2. Make sure that there is continuity [7-40 ohms at 20°C (68°F)]between terminal 3 and terminal 4 on the heated oxygen sensor connector.
3. If there is no continuity, replace the heated oxygen sensor.
NOTE: If the scan tool does not display the standard value although no abnormality is found by the above mentioned continuity test and harness check, replace the heated oxygen sensor (rear).