dumb question, pcv

ratrapp is right. also renew the rubber grommet and the metal screen below it. all MC for 20 bucks and you can forget it for 2 years.

if you search in here, you will find a ton of posts with little tips (i.e. Michael's tip about using a magnet to remove the screen, etc).

good luck.
 
Not a dumb question at all, It's hid back there pretty good. If you don't have one you might get you a service manual, has alot of info on component locations, service procedures, and specifications.