96 cav 2.4

sometimes while at idle the rpms will go up and down , also sometimes while taking off it will hesitate also going up a hill at speeds between 40 and 50 the rpm will bog down almost like a misfire I have replaced fuel filter ,spark plugs , plug boots , coils,throttle position sensor,idle air control valve,fuel pressure regulator,both o2 sensors ,engine coolant temp sensor,cam shaft position sensor ,crank shaft position sensor, intake air temp sensor ,map sensor, i also replaced most of the vacume lines , and some of the fuel lines around the fuel filter, also starter ,altenator,battery,and a bunch of suspension parts when I bought the car off of a friend she had told me that her father swapped out the 2.2 motor with a 2.4 motor I am stumped I dont no what else it could be I am very desperate please Help:confused:

mine does that too but usualy only if the engine has not warmed up before i take off, but once it is warmed up it does not do the idle thing or hesitate when taking off. but there is nothing wrong with your car, it is just like that for 2.4l's i think

My 96 cavi did the same thing last week..replaced all the same things, still doing it. I had to replace the whole fuel pump...which sucks cuz you have to take out the gas tank..runs like a champ now.