okay, this is the last time i promise. i have been having this lean-misfire w/ popping sound when i step on the gas tilla about 1500 rpms or a little below. after many suggestions i believe a guy who said he had a similar problem, he told me that it is a vacuum line at the upper intake. my mechanic/friend told me to check for air getting in after the MAF sensor, so i tightened everything up but the popping is still there, i JUST wanted to mention that also, from the idle-1500 rpm range, it gets really shaky (and almost feels like it "stutters" and is bogged down....my main question is, does that sound like a vacuum hose leak? after 1500 it pulls hard and is fine...