Alright, after literally hours of reading through old posts, I think I am close. I'll do the best I can explaining and I know one of you guys will get it... OK, started running rough out of the blue, so, after reading about the egr (does that mean Exhaust Gas Regulator?) I decided to try and find it. I took ok the air filter and assembly and found a vacuum hose that looked like it hooked on to a "stick of gum" (i read that earlier...that's my level of shop talk). Anyway, I unplugged that guy, truck started and ran, plugged it back in, and ran like crap. Suction is there...so what do I do next??? This is the greatest forum ever. Educate me!!!