QuestionWhat is the purpose and will it cause loss of power
AnswerHi Hug,
The EGR valve is used to lower the peak combustion chamber temperatures, and thus reduce the emissions of Oxides of Nitrogen.
When working properly, you never notice it, because you are cruising down the highway.
However, it is an item that is supposed to be cleaned periodically, and if sticking open, or not seating properly due to carbon, etc, it is just a huge vacuum leak.
So if it is dirty, it can cause a power loss, or poor performance.
Van