Description And Operation: Description: Notes

The heated oxygen sensor (HO2S) to detect the air/fuel ratio and send it to the Engine Control Module (ECM).
In order that this sensor operates properly, the temperature of the sensor tip must be higher than 370°C (698°F). For this reason, a heater controlled by the ECM duty signal, is built into the sensor.
When the exhaust gas temperature is lower than the specified value, the heater warms the sensor tip.