Oxygen Sensor: Testing and Inspection

OXYGEN (O2S) SENSORS

To perform a complete test of the O2S sensors and their circuitry, refer Powertrain Management/Computers and Control Systems/Testing and Inspection.

Testing and Inspection

To test the O2S sensors only, refer to the following:

Fig. 52 Downstream O2S - All:

The upstream O2S sensor is located on the exhaust pipe (Fig. 52).

Fig. 53 Downstream O2S:

The downstream O2S sensor is located on the outlet end of the catalytic converter (Fig. 53).

Each O2S heating element can be tested with an ohmmeter as follows:

Disconnect the O2S sensor connector. Connect the ohmmeter test leads across the white wire terminals of the sensor connector. Resistance should be between 4.5 +/- 0.5 ohms and 7 ohms. Replace the sensor if the ohmmeter displays an infinity (open) reading.