Oxygen (O2S) Sensor
WARNING: This page is about a different car, the 1994 Mazda 929. However, it is still accessible from the selected car via links, so may be relevant.
- Warm engine to operating temperature. Operate engine at idle. Disconnect O2S sensor electrical connector. Connect voltmeter between O2S sensor connector terminals "A" and "B". See Fig 1 .
- 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.