Oxygen (O2) Sensor

Oxygen (O2) Sensor(s) are threaded into exhaust manifold(s). Turn igniting off. Connect test harness between ECU and vehicle wire harness. Connect voltmeter between terminals specified in OXYGEN (O2) SENSOR TEST TERMINALS  table. Turn ignition on. If voltmeter does not indicate .4 - .5 volt when ignition is first turned on, and less than .1 volt in less than 2 minutes, check wiring between ECU and O2 sensor. If wiring is okay, replace O2 sensor.