1996 Ford Bronco Intermittent rough transmission shifting

I have a mystery probllem and I'm starting to think my computer is going. My transmission will randomly start to shift rough / the overdrive light will flash and my check engine light will come on. There is no warning when it happens, and then it will stop and everything will go back to normal. The first time it happened the computer had called out the speed sensor, so I changed it. Ran fine for awhile and then it started agin. My transmission was recently inspected and I was told that it is fine. The weirdest part of this mystery is when the problem is happening my horn doesn't work. As soon as everything goes back to normal. Beep beep.