Chevrolet Repair: EGR Valve 91 s10 4X4 4.3, oxides of nitrogen, vacuum leak

Question
What is the purpose and will it cause loss of power

Answer
Hi 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