!!!Major Transmission PROBLEM!!!

I have a 2003 pontiac grand prix gt, and when i go from a start or get on the gas hard in any gear or speed when the car wants to shift, it just rev's like its in neutral and i have to get off the gas for it to shift into the next gear. Its like that all the way thru the gears. i replaced the filter and added new fluid to it, and when we looked at the magnet and pan there wasnt any pieces of metal like anything broke or was grinding. This problem has been stumping me and about 4 master techs at my school UTI there is no code popping up on the scanners either. So we cant route it to anything.

This sounds like the pressure control solenoid is bad in the transmission based solely on your description. It isn't a DIY job but based on the fact that you have access to so much talent they may be able to help you replace it. If you take it to a tranny shop it will cost around $500 to replace.