rough idle, and acceleration, loss of power
 

hi all i got a 97 318i sedan 5 speed. have installed new plugs, wires ,air fiter. car has been running well. not much on low end but strong above 3500. and excellent milage too. 220k on the m44 motor. then all of a sudden boom, choppy idle , acceleration, hesitation and lack luster performance.on the highway it wont pull past 80 mph. ive cleaned the maf and icv. no change at all. im not much of a mech. so im at the end of my skill level. so b4 i take to my local german car guy is wondering if yall had any thoughts as to the problem so i dont just walk in blind to the problem. every thing i have seached leads back to maf, icv, or some other vac.leak....please help im out of ideas.

Does sounds like a vacuum hose problem. No CEL?

up date, i took the car to autozone and had it scanned. twice now it has put out code 4 # 1 cyl. missfire the first time i replaced the spark plug which was only 3 months old, but not the wire.was told i should just rep;ace all the wires and plugs. if just to rule out the coil pack or bad plugs. but guy also said a vacuum ;eak could throw out all sorts of bogus code too.