Impreza Coupe FWD F4-1820cc 1.8L SOHC (1995)
Heated Oxygen Sensor: Description and Operation
Heated Oxygen Sensor
Heated Oxygen Sensor
PURPOSE/OPERATION
The oxygen sensor measures the oxygen content in the exhaust and sends a voltage signal to the ECM. This sensor produces a measureable voltage
by comparing the amount of oxygen in the exhaust gas with the amount in the ambient air. The sensor operates only within a certain temperature
range of approximately 285 - 850°C (545 - 1530°F). The exhaust gases reach the outer surface of the oxygen sensor tip via the openings in the
protective sleeve. Ambient air reaches the sensor's inner surface via channels. The difference in oxygen content produces a voltage read by the
ECM. A heater is provided to allow the sensor to reach operating temperature faster, allowing ECM control of the A/F mixture sooner.
