EGR System - Diesel: Description
NOTE:
For 6.2L light duty emission, also refer to the DIESEL ELECTRONIC CONTROL SYSTEM article in COMPUTERIZED ENGINE CONTROLS section.
Purpose of the Exhaust Gas Recirculation (EGR) system is to limit formation of oxides of nitrogen (NOx) emissions. This is done by reducing peak combustion chamber temperatures during which NOx is formed. This is accomplished by reintroducing a small mount of exhaust gas into the combustion chamber, diluting the air/fuel mixture and thereby reducing NOx formation.
EGR system consists of EGR valve, Exhaust Pressure Regulator (EPR) valve and EGR/EPR solenoid assembly.