Good way to check is to start car, open hood, look at egr sideways and at the same time run up the rpm with your hand to about 2000rpm and you should be able to see piston on egr move. If not it is bad. Another way is to use a vacume pump as another person on this site just told me. Vacume pump cheap and can be used for a ton of stuff on a car. Egr should only activate at half throttle or so(crusing speed) NOT at idle or wide open throttle . Most Ford EGRs are specific to a paticular car and mine HAD to be purchased at Ford($75.) Make it simple . If you do replace it , take it with you when you go to buy the new one!!