Is there a cabin air filter in a 2001 Isuzu Rodeo and if so where is it?

There is only a pleated paper filter that is not replaceable. The only reason that I know it is there is because I ripped the dash out of one in the junk yard to get at the instrument panel. However, you can't order a replacement, so I think that is was meant to more or less keep large debris out of the system and not actually filter the air.