nope, the EGR just gives you better gas mileage when you are cruising. any other time it is closed and it doesnt matter. i didnt really lose any MPG from taking it off, but then again my car never did get good mileage.

i would cut the little end flanges off the ends of the tubes and then you can either weld those holes shut and rebolt them on or do what i did and RTV some coins in the holes. Mine hasnt leaked as of yet. i think i used a quarter and a nickel.