Kinda the same question.
I am kinda having the same problem except that reduced engine power message didnt start till I drove through some standing water on the road. My car died and I tried to start it. (trying to get my kids home in tornado weather) The next morning there was water in my air intake and my air filter was soaking wet. When I took my car to the shop they said that there was water in my oil. Now my reduce engine power message and check engine light come on every time it rains. Any suggestions what my problem might be? Did I damage my engine or flood it?