Oxygen Sensor: Testing and Inspection

HO2S Monitor

NOTE:
- Do not turn the ignition switch OFF.
- When the battery negative cable is disconnected, all readiness codes are cleared.

Required condition:
Ambient temperature between 20 - 95 °F (-7 - 35 °C).

1. Connect the scan tool to the Data Link Connector (DLC).
2. Start the engine, and hold it at 3,000 rpm with no load (in Park or neutral) until the radiator fan comes on.
3. Let the engine idle for 5 seconds.
4. Drive at a steady speed between 50 - 62 mph (80 - 100 km/h) for about 2 minutes.
5. With the transmission in D5 position, decelerate from 62 mph (100 km/h) by completely releasing the throttle with complete closed for at least 5 seconds. If the engine is stopped during this procedure, go to step 4 and do the procedure again.
6. Check for the readiness code with the scan tool.

HO2S Heater Monitor

NOTE: When the battery negative cable is disconnected, all readiness codes are cleared.

1. Connect the scan tool to the Data Link Connector (DLC).
2. Start the engine, and let the engine idle for 10 minutes.
3. Check for the readiness code with the scan tool.