I replaced my steering rack.  I removed the charcoal canister to access
the upper bolts to the driver's side rack brace.  I disconnect the
lower canister hose from the 'T'.  Of the remaining 2 hoses on the 'T',
one goes aft, my guess is the gas tank and the other to a small plastic
cylinder on  the inside fender wall at the bottom of the strut housing.
Somehow the small black plastic cylinder broke off the fender wall.
The cylinder appears to be a valve.  I see what appears to be a white
plastic ball, about 3/8" in diameter, that is backed by a spring.  The
ball can be pushed in easily.  I assume this is a relief to allow
outside air to mix with might be drawn from the gas tank up into the
canister thence either into the throttle body via the port before the
throttle plate or into the EGR pipe if open.

How does this plastic valve attach to the wall?  Am I correct in that
it's suppose to allow air in or is it suppose to be purging something?
I can see that it might not need to be filtered as in the case of the
BPT, the BPT having a foam filter to filter outside air (I happen to
find mine completely deteriorated allowing unfiltered air in; it
probably saw undue vacuum when the orifice in the BTP line to the EGR
pipe clogged with carbon).  Any air getting by that white ball would be
filtered by the charcoal canister.

So, what am I looking at with that valve hanging free?

Bill