Oxygen Sensor
- Remove 2-pin oxygen sensor connector from wiring harness socket. To check resistance of oxygen sensor heating element, connect an ohmmeter across WHT leads of oxygen sensor. Resistance should be approximately 4 ohms.
- Connect voltmeter between BLK lead of sensor and ground. Start engine. As engine temperature begins to rise, sensor will generate a low voltage signal.
- A lean mixture (caused by a small vacuum leak) will generate a voltage reading close to zero volts. A rich mixture will generate a voltage reading close to one volt. Reconnect sensor leads.