Oxygen Sensor: Testing and Inspection

OXYGEN SENSOR INSPECTION

Sensor Output Inspection

1. Connect the SST to the data link connector-2.




2. Select the "PID/DATA MONITOR" function and press TRIGGER.
3. Select "FHO2S", RHO2S" on the NGS tester display. NGS tester measures and shows the voltage.




Specification

4. If not as specified, inspect the following.
- On-board diagnostic system
- Intake manifold vacuum
- Fuel line pressure
If these systems are okay, replace the heated oxygen sensor.

Heater Resistance Test

1. Disconnect the heated oxygen sensor connector.
2. Measure the resistance between heated oxygen sensor terminals B and C [Front] or D and C [Rear] by using an ohmmeter.

Specification: Approximately 6 Ohms at 20°C (68°F)

3. It not as specified, replace the heated oxygen sensor.