Seems as though there's a missing tube or something that goes to my TPI...passenger's side of the throttle body, there's a loud hissing noise, coming from a vacuum of some sort. When I put my finger over it, it stalls the engine. I think it's got something to do with the smog, as there are no tubes going to or from my charcoal canister. Can somebody point me in the right direction?

 

is it a big or a small hole? it sounds to me like it could be for the PCV valve