i had it checked out, at a shop, the only one they found was for my a/c, but atleat now it dont just blow out my defrost

 

If they didn't smoke test it with a smoke machine ......there may be a hidden vaccum leak somewhere unknown to them...A smoke machine will find all vaccum leaks in less than a minute or two also you might want to try and clean the mass air meter with some special cleaner than napa or autozone sells