I read someone saying something about a pre-filter filter. Is there such a thing?

 

AEV has a cyclonic pre-filter as one of the options for the air inlet on their snorkel. The only other pre-filters that I know of are "jacket" style jobbies that slip over aftermarket CAI's.

If you're getting a snorkel and you spend a lot of time in dusty environments, the AEV setup is probably worth it.

 

I run a Donaldson Top-Spin Pre-Cleaner along with a specter performance in-line airbox....