Hopefully someone can offer me some good tech advice on this; I recently purchaced a 98gt with 40000mi and a week after I bought the car I my belt started squeelin after I hit 2500+ rpm. I found out the idler pulley was being held on the timing cover by the bolt only, and the hole that holds the bolt for it had cracked, so I replaced the timing and and to my surprise the squeeking sound returned. I recently added undrive pullys to the car and that did help anything either. Im curious as to what the sound could be coming from it seems to be coming from the area of the idler pulley and tensioner. Any ideas or help would be greatly appreciated!!!

either your tensioner needs replacing or your belt is too long, or stretched, which will require replacement  

Apparently the problem was the belt, I swapped out for a Goodyear GatorBack and damn what a difference that made. Not only has the sound stopped but Im not slipping on high shifts, that was another nasty side effect I didnt mention. But the important thing is everything is fixed and as soon as I take that lovely emissions test my babys gettin some long tubes and a x pipe. Thanks for the help to all those that responded and if anyone has some suggestions on some cheap and more importantly effective exhause parts/systems let me know.  

Well a good redneck tip is to rub a bar of soap (irish springs) on the belt it'll stop sqeelin...No lie True Tip