Federal and Canada

NOTE: Before checking, warm up the engine until the engine coolant temperature reaches 80 to 95~C (176 to 203~F).

1. Start the engine and allow it to reach operating temperature.

Oxygen Sensor, Test Hook-up:

2. Disconnect the oxygen sensor from the wire harness and connect a high impedance (greater than 1 Meg ohm input impedance) voltmeter between the oxygen sensor output connector and ground.

3. Increase engine rpm to approximately 1,500 rpm.
4. After approximately 70 seconds of operation at elevated rpm measure the output voltage of the oxygen sensor while changing engine rpm up and down slightly.
5. A properly operating oxygen sensor voltage signal should fluctuate between approximately 0.1 vdc and 0.9 vdc.
6. If voltage output is low or non-existant replace the oxygen sensor.