My freind removed his EGR valve while removing the emissions components (airpump, acv, and cat). When we start the engine its running extremly rough. We just finished replacing all the vacuum lines, gaskets and so forth that can cause these idle problems.
What is the main function of the EGR valve and can it cause the engine to run really rough??
Thanks

 

If you removed it, it can't cause the engine to idle rough.

A bad EGR if installed on the engine, can cause a rough idle if its diaphram is busted and leaking.

 

My car idles the same as it did before i removed mine.. you might have a gasket leak somwhere or maybe you forgot to plug a vac hole somwhere.

 

The blockoff plate material is also important. Wayne knows quite a bit about this, he had some engine issues and after like hours and hours of diagnosing he found the culprit to be the egr plate.

I've been told to fill the two holes that the egr valve connects and plug them, then use a block off plate. I cannot remember the right material to use, but im pretty sure that mine is brass or copper, the one that is that I ordered from mazdatrix. I would assume that they know what material is proper. Other than that I used a gasket with some sealer, but then again I have idle issues lol.