Closed Loop Control

This system is designed to control the air/fuel ratio precisely, so that the 3-way catalyst can minimize CO, HC, and NOx emissions simultaneously.

The system uses the exhaust gas sensor to give an indication of whether the air/fuel ratio is too rich or lean. The sensor transmits a signal to the E.C.C. control unit. The control unit adjusts the feedback signal so mixture ratio is right for the 3-way catalyst. During engine warm-up, system does not function until sensor reaches operating temperature.