Oxygen (O2) Sensor

The O2 sensor detects oxygen content in the exhaust gas and sends this information to the ECU. In operation, the ECU receives signals from the O2 sensor and varies the duration during which fuel is injected. A high voltage signal indicates a rich mixture. A low voltage signal indicates a lean mixture.

The O2 sensor is heated electrically for rapid warm-up and constant operating temperature. Power to the heating element is supplied whenever ignition switch is turned to ON position.