is it throwing a code?
best thing for you to do is get some dielectric grease, and some electrical connection cleaner and one by one, remove every electrical connnection you see, clean it, and apply grease. this will seal them all from moisture. this includes the spark wires.
personally, i've never had a problem, and I dont think we've heard much of it.
also, be sure to check your battery cables, clean them and grease them as well.
if that doesn't stop it, at least you eliminated something huge, but it almost certainly has to be water shorting something.