Oxygen Sensor: Description and Operation

The four Heated Oxygen Sensors (HO2S):
- are located in the dual converter Y pipe, two are below the exhaust manifolds and two are behind the catalytic converter.
- react with the oxygen in the exhaust gases and generate a voltage based on this reaction.
- A low voltage below a threshold indicates too much oxygen or a lean condition.
- A high voltage above a threshold indicates not enough oxygen or a rich condition.