Our C7 show a lot of restriction even after changing the filter. Last time Cat didn't have one of their filters and a different brand was installed.
Perhaps there is a certain filter that works better.
none of the ones we pulled out were very dirty even appearing almost new. Where the filter is and the intake high on the side of the coach I worry about water swelling the media and causing restriction.
perhaps I can figure out some sort of shield around the intake, on the side of the coach. Seems a terrible idea to put it there.