I have a 2000 GTP and if I manually shift it down to first then take off, it acts like it is slips then bangs a bit into gear and then goes fine. This will happen even when taking off easy from the light. If leave the trans in D or 3 then it works fine, even if I hard launch the car and spin the tires. I am thinking it could be somewhere in the valve body but I don't really have much experience with these transmissions. I know there is a pressure control solenoid problem with some of these transmissions, but Im not sure if it cause this symptom. I dont want to have to replace it if I dont need to, they are a pita to get to, and Im sure a trans shop would cost half and arm and maybe some leg.
Anyone ever seen this problem, or point me in the right direction?