93 ford probe GT Acceleration issue

I have a 93 ford probe GT 2.5 L V6 w/ around 186000 miles i just bought the car about 2 months ago and it was performing perfectly but in the past week its begun to sputter when i hit the gas it makes a loud noise like a boat motor and the rpms slowly rise while in gear but when im out of gear i can mash the gas with no problem... ive changed the air filter ive thrown some fuel additives in to clean the injectors i have new plugs and wires and the o2 sensors are new.. what else should i look at?

If you are still having this problem, it could be caused by the Crankshaft Positioning Sensor. I have a '93 PGT that had the same problem, it would make a roaring kind of sound but wouldn't go faster especially up hill. The check engine light was on and we got a code of 2 meaning the Crankshaft positioning sensor. The wires was eaten up by the belt due to someones stupidity before I bought it. It costed around $44.99 at Autozone. It runs like a beast now.