Dave, Yes I'm talking about the Hot/cold air valve D:07:01. Due to the location and without close examination and for the sake of a longer conversation and a lot of people know or have heard of a mass air flow meter. That's why I called it that. Your also correct in certain parts of the country and in certain weather conditions ( Freezing ) the air flow valve is necessary to keep the water in the fuel system from freezing. But, as I understand it, most of the cars in sub freezing weather are in storage due to not wanting to get the car in a potential accident and salt on the roads. In our southern part of the country, we may have a little potential freezing weather but it's not bad. Remembering that I have said I worked on Corvettes a lot with carburated systems, I'm used to power tuning a system. So if I have maximum fire, good hot grade of gasoline, maximum air flow using standard parts and with only minor changes and without a dyno test, I can feel the difference from beginning to now. Yes, it's not all that measurable by a dyno test, But have you ever got in a car and drove it and you feel you have to push hard on the gas to make it go. With what I have done, I now have the sensation the car is pulling me instead of me saying: gitty up go. I guess it's the old mechanic coming out in me. I have said in the past, the car will tell you a lot by the feel and the sounds. You just have to know how to read it. John Hervey www.specialTauto.com