So I've been wondering for a while what a certian vacume hose was, and everyone I talked to wonered too. Well I think I figured it out. The vacume hose in question is the one that conects to the back of the top half of the stock intake, before the MAF. It runs from there to the top of the intake manifold. Well I think I final know waht it is. It is my belief that this mystery hose is what suplys air for the IAC. Does anyone know for sure? Am I right? Mystery solved?