Exhaust Recirculation System - Known As EGR Valve

The Exhaust Gas Recirculation (EGR) system is used to lower Oxides of Nitrogen (NOx) emission levels caused by high combustion temperature. It does this by decreasing combustion temperature.

The main element of the system is the linear EGR valve. The EGR valve feeds small amounts of exhaust gas back into the combustion chamber. With the fuel / air mixture diluted by the exhaust gases, combustion temperatures are reduced.


Too much EGR flow at idle, cruise, or cold operation may cause any of the following conditions to occur:

• Engine stalls after cold start

• Engine stalls during closed throttle conditions

• Vehicle surges during cruise

• Rough idle

• DTC P0300 (misfire detected)

Too little or no EGR flow may allow combustion temperatures to get too high. This could cause the following symptoms:

• Spark knock (detonation)

• Engine overheating

• Emission test failure

• DTC P0401

• Poor fuel economy

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  • Guest - Edwin

    I will change the engine to my Dodge Caravan 2001. Will put engine in 2002. Work well one week after it failed. It stopped working two pistons, cables. Will change idle control and throttle, and continues with the bug. The engine 2001 original of my truck had a tube to the front which was going to escape through the top of the system this 2002.