my car threw a CEL so i had it read and that's what it read along with APP sensor, electronic connection failure. it'll go in and out of limp mode where the car won't let me go above 3k and it is EXTREMELY slow and weak. when it's not in limp mode i can feel the car jerk as if i were pumping the gas pedal when i'm putting just enough pressure to keep the speed constant on a level surface. the transition between on and off the gas is not smooth at all. there's moments of hesitation when i do press the gas to accelerate.

i'm having the car checked at the dealer tomorrow but i thought i'd see if anyone else has had this problem. is it an expensive fix? what caused it? etc. i apprecaite the help. it's an 04 coupe V6 6MT with 49k miles. thanks.