Oxygen Sensor Test

1. Using a Digital Volt Meter, connect the positive lead to the Oxygen Sensor Checker terminal (Figure 30). Connect the negative lead to a good ground on the engine block.


2. Connect a tachometer to the engine.

3. Start the engine and warm up the engine to normal operating temperature.

4. Idle the engine for 5 minutes. Check the maximum oxygen sensor voltage produced at idle and record the reading.

NOTE:
The Oxygen Sensor checker terminal has 2 electrical connectors. Connect the positive lead of the Digital Volt Ohm Meter to the connector with the shielded wire. If the voltmeter reads 0 Volts connect the positive lead to the other connector and recheck. If both readings are 0 Volts then the Oxygen Sensor is inoperative and replacement is necessary. The oxygen sensor voltage will vary continuously. Use only the highest voltage produced when checking.

5. If the maximum oxygen sensor voltage is less than 0.6 volts, replace the oxygen sensor.