Oxygen Sensor: Description and Operation

Heated Oxygen Sensor:

Oxygen Sensor Operation:

PURPOSE
Inform PCME, via a voltage signal, of exhaust gas oxygen content. PCME determines air/fuel ratio based on voltage generated and makes appropriate adjustments to maintain the optimum ratio of 14.7:1.

LOCATION
In exhaust pipe below exhaust manifold.

OPERATION
Sensor generates voltage according to exhaust gas oxygen content. Voltage range is approximately 0.1 - 1.0V. Voltage increases when oxygen content is low (rich) and decreases when oxygen content is high (lean). 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 PCME. To operate at peak efficiency, oxygen sensor must heat up to approximately 572 - 752°F (300 - 400°C). To reach temperature more quickly, sensor is equipped with a heating element.

CONSTRUCTION
Sensor incorporates a platinum coated ceramic zirconia tube which generates voltage if there is a difference in oxygen concentration between inside (exhaust gas) and outside (fresh air) of tube. To reach operating temperature more quickly, sensor is equipped with a heating element.