Oxygen Sensor: Description and Operation

PURPOSE / OPERATION
The heated oxygen sensor, installed in the exhaust system, monitors the oxygen content of the exhaust gases. A voltage signal from the oxygen sensor informs the powertrain control module as to the exhaust gas oxygen content (lean or rich condition). The powertrain control module will interpret the voltage signal and compensate for the indicated condition. The sensor incorporates a heater in it's design which allows it to start working much faster after engine start-up then the older non-heated design thus helping to limit cold start emissions.