Emission Controls (cont'd)
Engine Exhaust Controls
The engine exhaust emission control systems are designed to
control combustion during idle, acceleration, cruise, and deceleration.
These systems are entirely separate from the crankcase and
evaporative emission control systems described previously.
PGM-FI System
The PGM-FI system on this model is a sequential multiport fuel
injection. The PGM-FI system consists of three independent sub-
systems; Air Intake, Engine Control, and Fuel Control, thus
allowing more accurate control of air/fuel ratios under all
operating conditions. The Engine Control Module (ECM) detects
the amount of air drawn into the cylinders and determines the
amount of fuel to be injected to provide the optimum air/fuel ratio
for all engine needs.
Ignition Timing Control System
This system automatically controls the ignition timing to reduce
the amount of HC and NOx.
Three Way Catalytic Converter
The catalyst is used to convert hydrocarbons (HC), carbon
monoxide (CO) and oxides of nitrogen (NOx) in the exhaust gas,
to carbon dioxide (CO
2
), dinitrogen (N
2
) and water vapor.
Exhaust Gas Recirculation (EGR) System
The EGR system is designed to control the formation of oxides of
nitrogen (NOx) caused when fuel mixture burns at high
temperature. It works by recirculating exhaust gas through the
Exhaust Gas Recirculation valve and intake manifold into the
combustion chambers where it reduces peak temperature by
diluting the air/fuel mixture.
