I have a 2000 F-150. Recently, while driving (though not all the time) the overdrive will kick on and throw it into neutral. Then it kicks back into gear and is fine. It read a couple of different codes.

I replaced the shift solenoid and this seemed to help, then it started all over again. Took it to a transmission shop, and they could find nothing wrong with the transmission, but put a new brain in. It ran fine for a week, and started all over again. They put it back on computer and said it was one of the parts that we replaced. So we got a new one and it didn't help. Took it to a different shop and they replaced the pressure solenoid. It helped for about a day, then the engine light came on. It drives fine, then it doesn't, like there is a short somewhere but no one can seem to find the true problem. Any ideas?

I took my truck to my local transmission shop to get it looked at because it was slipping in over drive when i was doing 40-60mph. The shop told me the tranny is fine it has something to do with a random misfire at certain rpms. (No engine codes at this time). I took my truck home so I can change the spark plugs and start off there. Doing so I found that cylinder #4 the spark plug threads were pretty roached up they were only holding onto the spark plug with 1 thread. Murrays/O'Reilly autoparts has a healy core made for 4.6 and 5.4 triton engines for $65 + tax. Its a special order item (not in stock). My thought was if its only hanging on by one thread, I must be losing compression, so I bought it and installed in cylinder #4, took less than 10 min, no tap or reamer required. Really simple to do. Once healy core and spark plug were back in, started truck and did a 1 week test drive and so far the slipping that I thought was coming from tranny overdrive has gone away. It did turn out to be a misfire due to lack of compression in cylinder #4 thats why no engine codes, its not considered a misfire on the cars computer. If your looking for a compression issue on your truck, pull the spark plugs and look at the top half of the spark plug( the white porcelain piece) if its tan or brown from heat, might be a compression issue with that cylinder.