Emission Control Systems: Description and Operation

The emission control systems are used to reduce the following harmful gases in accordance with federal and state regulations:

^ Carbon Monoxide (CO)
^ Hydro-carbon (HC)
^ Oxides of Nitrogen (NOx)

This vehicle has the following major systems:

MULTI-PORT FUEL INJECTION (MFI) SYSTEM
The MFI system is made up of an Engine Control Module (ECM), various sensors and output devices. This system controls engine operation (i.e. A/F mixture and ignition timing) to reduce pollutants while maintaining optimum driveability conditions and reducing fuel consumption. This system is covered in greater detail in Computers and Control Systems.

CRANKCASE EMISSION CONTROL SYSTEM
The crankcase emission control system prevents blow-by gases from escaping into the atmosphere. The blow-by gases in the crankcase are routed, through various components, back into the intake manifold for combustion.

EVAPORATIVE EMISSION CONTROL SYSTEM
The evaporative control system prevents the escape of fuel vapors from the fuel tank and fuel injection into the atmosphere. It consists of various components, which collect and lead the fuel vapors to the intake manifold for combustion.

EXHAUST EMISSION CONTROL SYSTEM
The exhaust emission control system consists of a three-way catalytic converter and an exhaust gas recirculation (EGR) system.