Oxygen (O2S) Sensor
- Warm engine to operating temperature. Operate engine at idle. Disconnect O2S sensor electrical connector. Connect voltmeter between connector and ground. Increase engine speed to 3000 RPM until voltmeter indicates about .55 volt.
- Observe voltmeter while rapidly accelerating and decelerating engine speed. Voltage should be 0.5-1.0 volt during acceleration and 0.0-0.4 volt during deceleration. Replace O2S sensor as necessary.