I would replace the K&N filter with a dryflow from AEM on your intake. K&N filters let too much dirt through, the AEM filters alot better and it doesn't require oil, ford mafs don't like oil. I have seen alot of independant testing of air filters on the off/road forums, K&N gets very low marks on thier filtering ability, there the best flowing, but there's a price to be paid for all that flow, "dirt". I had the 77 series K&N intake on my ranger 4x4 with the AEM dryflow cone filter, worked great. AEM makes filters that fit other intakes besides thier own. The reason I didn't just use the AEM intake was that they didn't have one to fit my truck at the time as they do now.