Oxygen Sensor: Description and Operation

Oxygen Sensor Operation:

PURPOSE
Inform ECU, via a voltage signal, of exhaust gas oxygen content. ECU determines air/fuel ratio based on voltage generated and makes appropriate adjustments based on a variety of driving conditions.

LOCATION
Right side of engine compartment, in exhaust pipe forward of front converter.

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 ECU. To operate at peak efficiency, oxygen sensors must heat up to approximately 572 - 752°F (300 - 400°C).

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.