Exhaust Gas Oxygen Sensor

The exhaust gas oxygen sensor is threaded into the exhaust manifold and provides information to the ECU on the oxygen content of the exhaust gases. The sensor varies its output electrical signal to the ECU in response to the oxygen content.

The sensor monitors air/fuel ratio and generates 0.6-1.0 volt when surrounded by a rich exhaust gas mixture and less than 0.2 volt when surrounded by a lean mixture. This constantly changing voltage is sent to the ECU for analysis.