Air/Fuel Mixture: Description and Operation

The Multiport Fuel Injection (MFI) system is a system which employs the signals from the heated oxygen sensor to activate and control the injector installed in the manifold for each cylinder, thus precisely regulating the air fuel mixture ratio and reducing emissions.
1. Open Loop air/fuel ratio is controlled by information programmed into the Engine Control Module (ECM) .
2. Closed Loop air/fuel ratio is varied by the based on information supplied by the ECM oxygen sensor.