Air-fuel ratio control system (MFI multipoint fuel injection system) (Hyundai Santa Fe CM)

Using signals from the oxygen sensor, the Multiport Fuel Injection (MFI) system controls the timing and duration of the open state of the injector installed in the intake manifold for each cylinder in order to ensure an optimal air-fuel mixture composition and reduce exhaust toxicity.

Due to this, the exhaust gases produced by the engine correspond to a special composition, which makes it possible to use a three-way catalytic converter to reduce the concentration of toxic substances. The catalytic converter is used to convert the three main components of the exhaust gases ((1) unburned hydrocarbons (CH), (2) carbon monoxide (CO) and (3) nitrogen oxides (NOx)) into harmless substances. The distributed fuel injection (MFI) system can operate in two modes:

• open loop control of air-fuel mixture composition ("open-loop") is carried out in accordance with the data previously recorded in the electronic engine control unit;
• air-fuel ratio feedback control ("closed-loop") is carried out in accordance with the signals from the oxygen sensor received by the electronic engine control unit.

Information is copied from the website HyundaiBook