Oxygen (O2S) Sensor
WARNING: This page is about a different car, the 1994 Mazda MX-6 and 1994 Mazda 626. 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 "C" and "D" on 2.5L, or terminals "A" and "B" on 2.0L. 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.