Axxess 4WD L4-2389cc 2.4L SOHC MFI (KA24E) (1990)
Oxygen Sensor: Description and Operation
Oxygen Sensor
The oxygen (O2) sensor, which is mounted in the exhaust flow, monitors the amount of oxygen in the exhaust gas. The sensor has a closed tube
made of ceramic zirconia. The inner surface of the tube is is exposed to atmosphere while the outer surface is exposed to the exhaust gas. The
differences in oxygen content makes the sensor generate an electrical current. To enhance the generating capacity of the zirconia, the tube is coated
with platinum.
A richer A/F mixture equates to a higher voltage (approx. 1 volt).
A leaner A/F mixture equates to a lower voltage (approx 0.1 volt).
The ECU interprets the voltage change as the stoichiometric point and will attempt to control the injector duration, ignition timing and several
other systems to maintain that condition.