So other than this, my car is perfect, after finishing the headgasket job last week. No CEL or codes of any kind. But on the highway, if I push the gas pedal to a certain range (or if the cruise does it when going up a hill) it will start jerking, and stuttering. It loses power. If I floor it, it's fine. If I let off the gas, it's fine. It's a very narrow range of the throttle. It's almost like a really really bad misfire, but again no codes. Does anyone have any clue what this could be? New fuel filter.

Also, new gaskets all around. Did the UIM gasket twice, first one got broken and it was throwing a Fast idle code. vacuum hoses are all properly attatched, spraying Carb cleaner around the intake manifold area produces no noticeable RPM changes.

has the spark plugs been re-checked and cleaned?. Also how old are the upstream O2 sensor?.

Spark plugs are almost brand new, only about 1000 miles on them, and clean. Upstream O2 sensor is about 40,000 miles old, but again, no CEL or codes.

Throttle Position Sensor. My car was doing the same exact thing not long ago, replaced that, jackpot.

Weebel wrote:Im to smart to go to strip clubs.

i have had the same problem, it progressed to be much worse with in a few days, could hardly drive it then it was undriveable. in the end i replaced the coil's and icm and its been all good, i replaced with a complete idi cover off a junkyard donor so not sure which one it was exactly.

check the plugs, wires and cap if it has one...and more important...check the vacume lines. my cim had the same problem when the vacume like had a small hole in it...it tryed to stall...lost power...u name it.

http://www.cardomain.com/ride/3062549