Thread: Bucking on acceleration and stumbling idle at cold start

hey room, i have a 99 pontiac grand prix gt. i just got it back from the shop. replaced the intake gaskets, valve cover gaskets, and oil pan gaskets. also replaced int icm and all 3 coils. now when i accelerate, it starts bucking bad and on a cold start it idles like its gonna die. car has 111000 miles. no lights on at dash. also when i start the car and rev it up, i hear exhaust rattling? any ideas? could it be the cat that is causing this?

wires and plugs been bout a year since changed but the fuel filter was changed like 2 months ago. a few months ago the icm went and the car stank like gas comming out the exhaust. could it have fried the cat? no dash lights on though

ok found the problem i think. upon looking at the maf sensor i did notice that theer was a crack where i guess a seam was on the top of the sensor. i stuck my finger nail in it and the whole top half of the sensor came off and the gooey stuff inside was there. i closed it back and started engine. upon opening it up a little, i noticed the engine act like it was going to die and upon opening it up all the way the engine did die out. so i just unplugged it and started it up and drove it round a bit until i get the new maf in the mail. so far its not as bad bucking in acceleration. i went ahead and did order an new maf, throttle position sensor, and a new idle air control valve. also going to change the plug wires while im under there. hope this works. havent changed any of the sensors i bought yet so its prolly time. car has 111000 miles on it. hope the hesitation and bucking stops. ill keep u guys updated.

oh and all parts ordered from advance auto with delphi plug wires and all bwd brand sensors

alright. bucking is gone. before i changed wires and sensors, i decided to take plugs out and clean them and reset them in the engine. and thats it lol runs like a champ. oh and the sensors will be changed got them in today. hmmm wonder why maf sensor is still good??? it was literally cracked open? anwyaws lemme know what u think