R8244559AB | Genuine Mopar® EGR Exhaust Recirculation Valve For 6.7L 2007-2012

The main reason for having an EGR system is to reduce the formation of nitrogen oxides (NOₓ), which are pollutants formed in high-temperature combustion. 

• When combustion temperatures are very high, nitrogen (from air) and oxygen can combine to form NOₓ.

• By reintroducing a portion of inert exhaust gas back into the intake, the gas mixture is diluted, which lowers peak combustion temperatures.

• Lower temperatures = less NOₓ formation.

Also, in some engine designs, EGR helps with:

• Reducing “knock” or detonation in spark-ignited engines by moderating combustion temperature. 

• Improving efficiency under certain conditions by reducing pumping losses (in gasoline engines).

• Rough Idle / Unstable Idle

  • The engine may shake or run unevenly when idling (in park or neutral).

  • If the EGR valve is stuck open, it allows exhaust gas back into the intake at times when the engine needs pure fresh air, upsetting combustion.

• Reduced Engine Power / Poor Acceleration

  • The engine may feel sluggish, especially under load (e.g. uphill or passing). 

  • If the EGR is stuck open or stuck partially closed, the air–fuel mixture gets diluted or incorrect, reducing efficiency. 

• Engine Stalling

  • The car might stall at idle or when coming to a stop. 

  • Particularly happens if the EGR is stuck open, causing too much exhaust gas dilution at low RPMs. 

• Knocking / Pinging / Engine “Spark Knock”

  • If the EGR valve is stuck closed (i.e. no recirculation), combustion temperatures increase, which can cause pre-ignition / knock. 

  • This is more evident under load / acceleration.

• Check Engine Light (CEL) / Fault Codes

  • The ECU may detect improper EGR operation and log codes (e.g. “EGR flow insufficient,” “EGR circuit malfunction”). 

  • The CEL may accompany other symptoms. 

• Poor Fuel Economy / Increased Fuel Consumption

  • Because the air–fuel mixture is off, the engine may consume more fuel to compensate.

• Emissions / Failed Emissions Test

  • A malfunctioning EGR can cause increased NOₓ emissions or more unburnt hydrocarbons, possibly leading to a failed emissions test. 

  • Visible exhaust smoke or stronger fuel smell can accompany this. 

• Engine Overheating

  • If EGR is stuck closed, lack of cooling from recirculated gases can contribute to higher combustion temperatures, which can worsen engine heat.