i have a 01 gt that im not sure if i have a possible trans issue or what it is? it will drive fine under light throttle and shift fine but if your going say 25 and floor it it will not shift but just go up to around 5k and stay there till you let off then it will shift. if your doing around 45-55 and floor it all it does is down shift and the rpm will go to about 4200 and stay there and wont really go faster than 60 mph unless you let off then it will shift and you can go faster? i just did plugs and wires but didnt really help. what could it possibly be? the car has 124k and just had the trans flushed and the new fluid still looks perfect. thanks