There is no "problem" with the charcoal filter. It doesn't hurt performance any. And the factory air box already has a direct inlet that gets fresh air from in front of radiator. Cutting a hole in the side and adding another hose did nothing to help.I can't believe that no one has had this problem about that upper filter.If i remove it I think I would get more air. I also ran a 3 in in hose to the side of the air box from the area back of the grill area.