1996 mercedes c280 v6 misfiring on cylinder 4

Question

Been having this issue with this car, almost every time i exit the freeway the car shakes and has a loss of power (car is slow so i have to floor it to pass someone). Ive replaced all 3 coils and all spark plugs on this car less than a year ago. What would i need to replace now or maybe something is lose? or can it be other issues?