hi,
i didn't take it out, as i couldn't see how it could come out. some have punched holes in it, which seems counterproductive?
i just got the tank out of the car, sprayed brake cleaner in there and 'whisked' w/ a small paint brush, turn upside down, etc... seemed to work. be careful not to punch it.
Thank you for answering!
I think you are right.
What kind of symptoms did you have ?