tacomedic135

good morning everyone Im needing to pick everyones brain on a problem that has be stumped I've got a 2007 F-150 4x4 wilt a 4.6L and 204000 miles on it this past summer I started having problems when driving the speedometer would peg all the way to the right the trucks rpms would start fluctuating from about 1200 to 1500 rpm and the truck would go into limp mode I couldn't give it gas I couldn't do anything except coast to a stop it didn't matter if I was on the highway or in the city just out of the blue it would do it and when it would do this I would eventualy get a trans fault on my message center on the dash board. I could stop turn the pick up off and let it sit a minuet start it up and it would run fine. I would get codes of p0297 which is a vehicle overspeed condition and p0721 which is a output shaft sensor fault. ive replaced the OSS and the TSS and the VSS in the rear end. everything ohm'ed out good and best I could tell I haven't seen any shorts in the wiring harness. I purchased a new PCM as the next logical step and then It stopped giving me this problem for about 6 months and then two weeks ago it started doing it again I replaced the PCM and it did again probly the worse ive ever seen it do. Im all out of ideas and things to check and out of ideas everything else is awesome on the truck as all f-150s are its so sparatic on when it wants to act up theres no pattern when it does this except it seems as though it does it more often when its raining or driving through a big puddle thanks in advance for your help