626 Tranny-blues

[skibear]

OK..here goes, my '97 626 was running fine then a Pepsi was dumped in the center console (can we say electronic nightmare?), since then I've had it in the shop for used "brain" replacement 3 times and also the "shift diagnostic module?" in the tranny. The poor beast starts out fine in 1st, still revs high and misses 2nd gear and goes into 3rd and then pulses in and out of 4th (overdrive). It's kicking a couple codes which no one seems to know what they are. Wondering if there's something else electronic hiding somewhere that the "brain" might have "kicked" when it took the Pepsi challenge! I've found a couple of trannys but don't want to invest if it won't change anything due to system failure elsewhere. I'm thinking dynamite to clean it out, but it's too nice of a car. Ideas?? Anyways....thanks up-front for any help and oh yeah...have a Merry Christmas!