Intake noise, help plz.. Options

[mikecelica]

Its been a while now that my cars had this hissing kinda sound like air escaping from somewhere..i hear it its under the hood (no exhaust problems, checked). i think it might be the intake tube. The tube is conected to the intake manifiold, and a cone filter at the end. on the tube tho thers two holes, one for the air sensor,but whats the other for? it has a little nipple and it came wit a rubber thin hose but im not sure is it suposed to plug into somewhere of the engine/manifold? any helps. thanks

[tonytutino]

for the GT model, that hole is for a hose that comes off of your valve cover. but since you have an ST, nothing goes there. just go to autozone and buy a vaccuum cap bro, thats what i did.

but that hissing... its probably just the intake itself. mine hisses like a snake