Hyundai Elantra: Description and Operation - Exhaust Emission Control System - Emission Control System - Hyundai Elantra HD 2006Ц2010 Service ManualHyundai Elantra: Description and Operation


Description

Exhaust emissions (CO, HC, NOx) are controlled by a combination of engine modifications and the addition of special control components.
Modifications to the combustion chamber, intake manifold, camshaft and ignition system form the basic control system.
These items have been integrated into a highly effective system which controls exhaust emissions while maintaining good driveability and fuel economy.
Air/fuel Mixture Control System [Multiport Fuel Injection (MFI) System]
The MFI system is a system which uses the signals from the heated oxygen sensor to activate and control the injector installed in the manifold for each cylinder, thus precisely regulating the air/fuel mixture ratio and reducing emissions.
This in turn allows the engine to produce exhaust gases of the proper composition to permit the use of a three way catalyst. The three way catalyst is designed to convert the three pollutants (1) hydrocarbons (HC), (2) carbon monoxide (CO), and (3) oxides of nitrogen (NOx) into harmless substances. There are two operating modes in the MFI system.
1.
Open Loop air/fuel ratio is controlled by information programmed into the ECM.
2.
Closed Loop air/fuel ratio is adjusted by the ECM based on information supplied by the oxygen sensor.

    CVVT (Continuously Variable Valve Timing) System. Description and Operation
    Description The CVVT (Continuously Variable Valve Timing) which is installed on the exhaust camshaft controls intake valve open and close timing in order to improve engine performance. ...