Oxygen Sensor: Description and Operation

Fig. 9 Exhaust gas oxygen (EGO) sensor:

The EGO, Fig. 9, sensor supplies the ECA assembly with a rich or lean condition during engine operation. On 4-97.6 and 4-140 engines, the EGO sensor is threaded into the center of the exhaust manifold. On V6 engines, the EGO sensor is threaded into the rear portion of the left and right exhaust manifold assemblies. On V8 engines, the EGO sensor is threaded into the rear portion of the right exhaust manifold assembly.