Yea I was wondering about that clean air,dirty air thing. But Im not all that smart so I didnt want to ask. I was thinking maybe it was related to that dirty bomb thing the news folks are always going on about. Anyway another question. If some of you have the time. What kind of gas milage are you getting running the freak. Also do you think maybe we have lost some bottom end power with the freak. Again im sorry for some of the spelling and grammer errors in this and previous post. It just never seems to come out on the screen the way im thinking it.