Description And Operation: Description
Heated Oxygen Sensor (HO2S), consisting of zirconium and alumina, is installed on both upstream and downstream of the Manifold Catalytic Converter (MCC) to detect the air/fuel ratio and send it to the ECM. The sensor output voltage varies in accordance with the air/fuel ratio.
The sensor must be hot in order to operate normally. To keep it hot, the sensor has a heater which is controlled by the ECM via a duty cycle signal. When the exhaust gas temperature is lower than the specified value, the heater warms the sensor tip.