Oxygen (O2) Sensor

The O2 sensor produces a small electrical voltage (.1-.9 volt) when exposed to oxygen in exhaust gas flow. O2 sensor is electrically heated for faster switching. Heating element is powered through ASD relay.

The O2 sensor acts like a rich/lean (air/fuel ratio) switch by monitoring the oxygen content in exhaust gas. This information is used by SBEC to adjust air/fuel ratio.

The O2 sensor produces a low voltage when oxygen content in exhaust gas is high; when oxygen content in exhaust gas is low, it produces a higher voltage.