Oxygen Sensor

This sensor is mounted in the exhaust manifold. It supplies a low voltage when fuel mixture is lean (too much oxygen) and a higher voltage when fuel mixture is rich (not enough oxygen). Oxygen sensor must be over 600°F (315°C) to function properly. The oxygen sensor measures quantity of oxygen only.

No attempt should be made to measure oxygen sensor voltage output. Current drain of conventional voltmeters could permanently damage sensor, shift sensor calibration range and/or render sensor unusable. Do not connect jumper wire, test leads or other electrical connectors to sensor. Use these devices only on ECM side of harness after disconnecting from sensor.