So guys I have a 99f250. 284k 4" exhaust on SCT X4. Trans recently started to act up. Here is what it does and what I've done replacing things. Absolutely will not shift out of fist gear without letting off the throttle. Unless I start in second, which then I have to shift up into drive. When in OD, truck will randomly shift itself out of fear and into a neutral type state, I can mash the gas and all I see is rpms, until one of two things occurs, either i let the truck slow down to under 40mph, which is then downshifting on its own into 3rd, or I press the OD button on and off quick, which then it will shift itself back into OD and drive fine until it decides to be a dick again and go back into the neutral like state. I have replaced the park safety switch, have replaced the coolant temp sensor, just because my tuner was reading -200F at start up idle. I do not have a scan tool. I replaced the trans fluid and filter, old trans fluid was still red and had no burnt smell to it what so ever... So guys. Serious input. What could be wrong. This all happened out of the blue, parked it one night, woke up and drove it the next morning when all this happened.