hello again, previously posted about my problem with a hesitation under light throttle around 1800-2000 rpm in my 98 auto, all stock, i believe i have found the culprit just not sure what the cure is, after close inspection and cleaning of everything imaginable and replacing my front o2 sensor, i remember being told that the egr opens at around the rpm condition exists. so i pulled the line off egr and plugged it and hesitation gone, so the question remains, why? well i'll tell you what i know, i vacuum tested it and it opens and closes,also opens when you twist throttle, i cleaned the whole inside where it closes and seats, i did notice that in my service manual there is a reference that it should open about 1/8 inch, mine seems to open more than that more like a 1/4 inch, which would kinda explain the hesitation cause it's dropping too much vacuum and leaning the mixture out and sucking too much exhaust in, right? so is it opening too far and if so any ideas why, i see there is some kind of vacuum modulator"looks like a flying saucer" with two vac lines in, one out to egr vacuum purge valve and another line that runs down to manifold next to egr. could it be faulty? any way to test it, or could return spring in egr valve weakened?i would be perfectly happy leaving it unplugged but it is kicking a egr code with line unhooked, thanks, and thank you to all who responded to my previous posts,