TIBURON(GK) >2004 > G 2.7 DOHC > Emission Control System > Exhaust Emission Control System>Description and Operation  
OPERATION
AIR/FUEL MIXTURE RATIO CONTROL SYSTEM [Multiport Fuel Injection (MFI) System]
The MFI system employs the signals from the heated oxygen sensor to activate and control the injector installed in the manifold for each cylinder, precisely regulating the air/ fuel mixture ratio and reducing emissions.
1.
Open loop-air/fuel ratio is controlled by information programmed into the PCM during the manufacturing process.
2.
Closed loop-air/fuel ratio varies by the PCM based on information supplied by the heated oxygen sensor.