Oxygen Sensor: Description and Operation

The oxygen sensor generates a voltage according to the ratio of oxygen in the ambiant air compared to the exhaust gases. The voltage changes in relation to the air/fuel mixture. When there is alot of oxygen in the exhaust (lean mixture),
the oxygen sensor will not generate much voltage (near zero volts). When there is not much oxygen in the exhaust, (rich mixture) the oxygen sensor will generate up to one volt.
The oxygen sensor is installed in the catalytic convertor and is connected to a tube with a shield cap.