323 L4-1800cc 1.8L OHC (1991)
Oxygen Sensor: Description and Operation
Oxygen Sensor
Oxygen Sensor Operation
The oxygen sensor generates voltage according to exhaust gas oxygen content. It incorporates a platinum coated ceramic zirconia tube which generates
voltage if there is a difference in oxygen concentration between the inside and outside of the tube. The voltage range is approximately 0.1 - 1.0V.
Voltage increases when oxygen content is low (rich) and decreases when oxygen content is high (lean). The ECU determines air/fuel ratio based on the
voltage generated and makes appropriate adjustments to maintain the optimum ratio of 14.7:1. The difference in oxygen concentration changes greatly
in the area of optimum air/fuel ratio, resulting in large voltage changes that are easily calculated by the ECU. To operate at peak efficiency, the oxygen
sensor must heat up to approximately 300 - 400°C (572 - 752°F).
