Pictures will help.
There is, on the passenger side of the vehicle, behind the grille an opening for the air intake. A sort of ram air intake. That ultimately feeds into the air filter box which then feeds air into the throttle body. I believe that intake passes thru some sort of mixer valve that also gets air off the manifold or routes some of the air over the manifold. The purpose is to semi-regulate the input air temperature.
I have no idea how good/bad that works. There is an air charge temperature sensor in the throttle body so independent of how well it works the engine does adjust to air temperature.
I know folks remove the stock air filter box and go to an under hood "cold air intake" which seems odd to me cause air under the hood is probably warmer after going thru the radiator than the actual air intake that gets air thru that box. Though with the mixing valve the under hood intake may not be as warm as the stock intake after the air gets mixed with heated air.
I expect the mixing arrangement has something to do with optimizing emissions.
