I think cleaning the AFM with compressed air may have damaged it. Should only use contact cleaner, and even then be very careful.
Have you got a cold air duct feeding you new partition? If not, maybe not enough air is getting through to the induction system (ie: you are suffucating the engine).
Another theory is that the condensed air, you mentioned, is playing tricks on the ecu and is causing it to splutter. I remember my car didn't like the fmic, pod, 11psi boost and cold nights, until i replaced the ecu with a programmable one.