EGR System: Description

The Exhaust Gas Recirculation (EGR) system is designed to reduce oxides of nitrogen (NOx) emissions by lowering combustion temperatures. A metered amount of exhaust gas is recirculated into the intake manifold and mixed with the air/fuel mixture.

There are 5 types of EGR systems used: pulse width modulated, electronic, digital and backpressure (positive and negative) systems.