What is an Oxygen Sensor?
An oxygen sensor (o2 sensor) is used to sense the comparative rich or lean fuel to air mixture being burnt by the engine. It feeds this information to the cars computer where the information is used to adjust the fuel injection, ignition and sometimes camshaft timing. Failure of an o2 sensor coupled with extensive driving after it has turned on the check engine light can lead to poor emissions and failed catalytic converters. A second o2 sensor is located behind the catalytic converter to monitor its efficiency.
