Oxygen Sensor: Description and Operation

Oxygen Sensor:

Oxygen Sensor Operation:

This system utilizes two oxygen sensors, located one each in the left and right exhaust pipes. The sensors generate voltage according to exhaust gas oxygen content. They incorporate 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, oxygen sensors must heat up to approximately 300 - 400°C (572 - 752°F). To reach this temperature more quickly, the sensors are equipped with heating elements activated by the ECU through a relay.