does this make sense to anyone else?:
well if you have no BOV then when the throttle body closes, the boosted air travels back through the intercooler and through the turbo with the flutter sound as mentioned above from the air being 'chopped up'.
Then, the air passes trhough the AFM, which is a wire that cools with the flow of air thus the amount of cooling determines the airflow. So the AFM detects the air coming back out of the intake system and thinks its sucking air in so adds enough fuel to compensate.
Result? the car blows a puff of black smoke as its just run real rich for a second...
thus its bad for environment and the EPA is right (again!)
OR, am i completely wrong? (wouldn't be the first time...)