It rattles when I shake it like it's supposed to, but if I blow or suck on the hose end of it, air flows freely. Isn't it supposed to block flow in one direction?
16 bucks for Motorcraft although aftermarket is $4 plus the hose is pretty cracked so another $13. Could this be why it goes to over 2000 rpm on a cold start for a few seconds?
do not forget the hose and passage into the intake. They can have sime buildup and plug, also seen the liner separate and collapse. If you replace do not get cheap hose.
Don't use fuel line hose, too thin. When ever I've replaced hoses I used automatic transmission hose, thicker wall. If your replacing the PCV replace the hose too.