I'm not sure which EGR code you had. (i've seen inadequate flow and excessive flow on recent Fords.) I also have a 98 SE sport w/ V6. Mine had been throwing the inadequate EGR flow, initially sporadically, then continously. I found that the problem was not the EGR valve. Mine had clogged up the passages leading to the intake from the EGR valve. I removed the throttle body, (make sure the gasket comes off the intake, the passage is part of the intake manifold, but hidden behind the throttle body gasket.) A can of spray carb cleaner and a small scewdriver (to scrape the carbon out) fixed the problem. Stuff a rag in the intake before you start spraying the carb cleaner, otherwise you may send a bunch of black goo up the intake manifold.
It's been about 5K since, no codes. (Current total mileage 138K) Total time was less than an hour. Hope it helps.
