Engine Cold Air Intake question

Cold Air Intake question

I just got a cold air intake but the big pipe does not have a port for the vacuum tube that used to plug into the old filter box. Does anyone know what is the function of that vacuum tube? Can this tube just be plugged?

It can not be plugged. Fortunately, there is an easy fix. Go to Autozone or wherever you can find one and purchase a little round PCV filter with like 1/2" diameter opening or so.

This is the EVAP fresh air port. The one that ticks is the purge valve. When it opens, fuel vapors are sucked into the intake manifold from the charcoal canister. This causes a vacuum to build up in the gas tank. So, this other valve (the one we're talking about here) opens to suck fresh air into the tank to equalize pressure. It only needs fresh/filtered air - that's the only reason it was plugged into the air box. Cheaper to just use the intake air filter than providing a special filter for it.

With the engine running, put your finger over the tube and you'll feel it intermittently open and suck air in (if the purge valve is ticking, that is). Just buy a little filter for it or just wrap a 2 sq. in. section of a t-shirt over it....just anything to filter the air, really. Whatever - pantyhose.

Late,
Trav