Oxygen Sensor: Description and Operation

Fig. 6 Exhaust gas oxygen sensor:

The exhaust gas oxygen (EGO) sensor, Fig. 6, senses the oxygen content in the exhaust. The EGO sensor supplies the ECA with a feedback signal which indicates a rich or lean condition throughout engine operation. The ECA uses this information for the control of air/fuel ratio. The EGO sensor is threaded into the exhaust manifold assembly.