Oxygen Sensor: Description and Operation

Oxygen Sensor:

PURPOSE
The oxygen sensors (2) measure the oxygen content in the exhaust and sends a voltage signal to the ECU.

LOCATION
The oxygen sensor is mounted in the exhaust, upstream of each front catalyst.

CONSTRUCTION
The sensor consists of a steel housing, sensor tip and its protective sleeve. The sensor tip itself is made from a platinum covered zirconium-oxide pipe. The sensor is also equipped with a ceramic heater.

OPERATION
This sensor produces a measureable voltage by comparing the amount of oxygen in the exhaust gas with the amount in the ambient air.

The sensor operates only within a certain temperature range of approx. 545 - 1530°F (285 - 850°C).

The exhaust gases reach the outer surface of the oxygen sensor tip via the openings in the protective sleeve. Ambient air reaches the sensor's inner surface via channels. The differance in oxygen content produces a voltage read by the ECU.

A heater is provided to allow the sensor to reach operating temperature faster, therefore allowing the ECM to control the A/F mixture sooner.