Heated Oxygen Sensors (HO2S)
WARNING: This page is about a different car, the 2010 Mercury Mariner and 2010 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.
The HO2S provide the PCM with voltage and frequency information related to the oxygen content of the exhaust gas. For additional information on the HO2S, refer to ENGINE CONTROL COMPONENTS .