5. Disconnect The O2 Sensor

Turn the ignition off.

Disconnect the O2 Sensor harness connector of the affected sensor.

NOTE: Check connectors - Clean/repair as necessary.

Turn the ignition on.

With the DRB III(R), monitor the O2 Sensor Signal voltage.

Is the O2 Sensor voltage more than 0.15 volts?

Yes >>
NOTE: Determine the cause of any contamination before replacing the sensor. Inspect for the following before replacing the O2 Sensor.
- Fuel contamination.
- Engine oil or coolant consumption.
- Use of improper RTV sealant.

Replace the O2 Sensor if none of the above conditions are present. See FUEL SYSTEM article.