I drove through a monsoon (Ok maybe it was just heavy rain) the other day commuting to work. My mini started missing and I couldn't get the rpm's over 1k. I pulled over and let it dry out. I was able to get to work but it was stalling at stop lights, and just not running very well. When I got it home I pulled the plug boots and made sure everything was dry. Now for a week it still will stall at stop lights (about 5% of the time) It misses a bit when under a load but above 2k it seems ok.
I checked codes and get 0107 which points to the map sensor.. I could try replacing that, but sometimes the sensor isn't the problem, it is just reporting a bad condition. Any ideas?

perhaps I should try this..

http://www.mini2.com/forum/first-gen...e-how-fix.html

Did you check your airfilter......some cai can get a wet filter. If this happened you got lucky...extremly heavy rain injested into the motor can cause it to fail....one of the risks of a open cone type cai.