Could this be from a bad EGR valve?

i have a 93 plymouth sundance with the 2.5 and for a while now when ever i do a short throttle burst at low speeds like you do when your just trying to pull forward just a little bit it stumbles really bad but than after like 2seconds it stops and runs fine... the other day i did it in reverse and it was the 1st time that the car actually stalled on me... i heard problems like this could be linked to the egr valve so i check my haynes book and tested the egr but i didn't see the plunger move at all but just a couple weeks ago the car ped deq with flying colors and this problem was way before than so could it even be the egr valve? ive also recently have had horrible gas mileage.. i mean horrible as in 14mpg and ive done a tune-up, vacuum lines, MAP sensor and injector and i dont have a fuel leak..please help thankls a lot