Service manual

G420F(FE) Service Manual Chapter 5. Engine Management System (EMS) 187
MPI Gasoline System Operation
The MPI Gasoline System of G420F engine is the
same as that of G420FE engine. See, “MPI Gaso-
line System Operation of G420FE EMS overview”
Electronic Throttle System
The electronic throttle system of G420F engine is
the same as that of G420FE engine. See, “Electro-
nic throttle system of G420FE EMS overview”
Ignition System
The Ignition system of G420F engine is the same as
that of G420FE engine. See, “Ignition system of
G420FE EMS overview”
Exhaust System
Heated Exhaust Gas Oxygen Sensors (HEGO)
G420F MPI Gasoline system utilizes one HEGO
(O2) sensor. It is a pre-catalyst sensor that detects
the amount of oxygen in the exhaust stream and is
considered the primary control point. Based upon
the O2 sensor feedback, the MI-07 system supplies
a optimized air-fuel.
G420F LP system does not utilize HEGO sensor
because it is open-loop system.
Figure 18. HEGO (O2) Sensor
SECM
The SECM of G420F engine is the same as that of
G420FE engine. See, “SECM of G420FE EMS over-
view”