Originally Posted by Android
Check your "facts" the reason has nothing to do with EPA. If so then why would the CVO bikes have opened up air intakes?
Stock box and K&N filter is the best bang for the buck hands down.
I believe the reason for the stock air cleaner housing is to quiet down the intake noise, probably for the EPA mandated noise standards on vehicles. When the twin cam originally was designed, it was made so most of the covers did not support moving parts (unlike previous H-D engines) to quiet the engine down, to meet EPA mandated requirements. Many years ago on here this was all discussed.
As to why the CVO's have open air filters, I can't answer that. Maybe because they are limited production?