Hyundai Elantra MD/UD: Heated Oxygen Sensor (HO2S). Description
and Operation
Description
Heated Oxygen Sensor (HO2S) consists of zirconium and alumina and is installed
both upstream and downstream of the Catalytic Converter. It 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.
