K&N filters don't filter well, they flow so good, they flow dirt through as well. The
AEM brute force intake is a better choice as they use the dryflow filter that requires no oil. Ford mafs don't function prroperly with oil on them.
K&N is old school, theres much better filters available now. In independant testing,
K&N ranked at the bottom for filtering ability, AEM, aimsoil and airaid were some of the better ones.