Thread: Help 04 Grand Prix stutter hesitation bucking wtf???

hey yall

so i am having problems with this 04 grand prix. hopefully someone here can help
totally stock except a magnaflow cat.

the car hesitates bad at 1500rpm, any other RPM its fine. also when i romp on it sometimes the power surges. no check engine lights

sometimes the car will stall when first started. i dont know if this is related.

i tried all new plugs and wires. autolite plugs gapped at .50

i am leaning toward an electircal issue.
gonna try cleaning the throttle body and mass air flow first.
then replacing the MAP and IAT senors.

in addition the gas cap warning comes on sparatically

ANYBODY????

MAF would be a good place to start. I do believe the IAT is part of the MAF sensor. Replace the gas cap with one from the dealership. We have had a flood of customers bringing their cars in for small evap system leaks/gas cap warnings. They have all claimed to have replced the caps but the light still comes on. Smoke test shows 90% of the after-market caps leak just enough to trigger the light/DTC.

The MAF may be the problem. Short of checking volumetric efficiency, its hard to verify.