Heated Oxygen Sensor (HO2S)

The heated oxygen sensors (HO2S) (9F472) react with the oxygen in the exhaust gases and generate a voltage based on this reaction as follows:

• A low voltage indicates too much oxygen or a lean condition.
• A high voltage indicates not enough oxygen or a rich condition.

The heated oxygen sensors are located in the exhaust pipes or the exhaust manifolds, depending upon application.