Ranger 2WD V6-245 4.0L VIN X SFI (1997)
Oxygen Sensor: Description and Operation
Heated Oxygen Sensor (HO2S)
The EEC-IV systems use only one Heated Oxygen Sensor (HO2S) for engine control. The EEC-V system uses two HO2S's. One for engine control
and the other for catalyst monitoring.
The heated oxygen sensor reacts with the oxygen in the exhaust gases and generate a voltage based on this reaction. 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 between the exhaust manifolds and the catalyst can.
