So I have a 97 grand prix 3.8sc. First I was having some rom bounce in od and problem from 4th to 3rd downshift. Took it too a tranny guy andbhe told me to do a tune up. I cant afford one at the moment so I put my stock wires back on (had msd from coils to wires) and a set of rapidfire plugs I had gotten a year ago and decided to go with the factory plug. It helped the problem but wasnt quite fixed. I got still feel a slight miss. One day I drove 60 miles and it was fine. It sat for a hour and went I left ibwent maybe a mile went went to turn onto another road and it bucked and shuttered like it had a major miss and did till i put fresh gas in. ( found a can of mountain dew in feont of my car that was fresh and empty and not there when I got home...) and 2 days later going down the highway it felt and by rpm looked like my torque converter unlocked and would not lock back up. I was at 2000rpm at 55mph and 2500 at 75mph. Where im normally 4-500rpm lower. I heard a faulty tps would cause some of this so I grabbed one out of a 97 gt and it didnt really help. I havent driven more then 20 miles since the sensor was put in. Whats your opinion, fixable or time for a new trans?