On our 04 Allure 40', it is on the passenger side, at the very tail of the coach. You have to drop and move part of the brackets of the Country Coach advertisement
! (The solid rock protection.) to access the clearner.
Just changed ours for the first time that we have had the coach, and it looked in pretty good shape. Air intake is up a bit, so suspect that helps.
Any chance yours was not sealed in tight, and it allowed a bit more 'stuff' in?
Best,
Smitty