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
