I'd suggest getting rid of the k&n filter though.. many many "studies" have shown that they let a meaningful amount more dust unto the motor when compared to a paper filter.. even when properly oiled. Another thing is.. when an oil filter gets dirty enough.. it starts letting even MORE stuff into the motor.. compared to a paper filter.. when they get that dirty they don't even let AIR through.. let alone contaminants.
Really.. do some deep digging on k&n filters. You'll be surprised at how poorly they filter. The dustier the environment.. the worse is is.. and the saltbelt suuucks for dust. They use so much salt&calcium on the roads up here.. when the roads are dry.. traffic will kick up an incredible amount of dust. Allllmost as bad as driving down a bone dry dirt road... literally..
Dust from dirt is bad enough.. but you DEFINITELY don't want to be sucking up dust that's corrosive.
If you have seen many many studies that show K&N filters let a meaningful amount of dust through, the studies are either flawed or they don't know what meaningful means.
I have a total of almost 500K miles on two different Rangers with K&N fair filters on them and there was absolutely no sign the filters let a meaningful amount of dust through. I had the oil analyzed on my 89 STX each oil change and there was no indication of dust getting into the engine. With almost 200K miles on it when I sold it to a co-worker, it used no more oil than it did when I bought it new. My current 02 FX4 is approaching 300K miles and it too uses no more oil than it did when I bought it new. So, if K&N filters pass dust, it certainly is not meaningful or the rings would be worn and those engines would use more oil.
I typically spend 4 weeks every year off-road in dusty conditions. I travel with groups and usually eat a lot of dust that is kicked up. When I clean the filter after the trips, it is caked up heavily with dust on the front side. The back side is as clean as the last time I cleaned it with that pinkish color still showing. I also wipe the inside of the intake tube with a white cloth and there has not been any sign of dust.
If you want to trust those studies, that is up to you. I prefer to trust the 500K miles of experience I have with K&N air filters. I am not trying to sell you on them, I just don't like bad advice being advertised. Of course, K&N air filters must be cleaned and oiled properly for them to work right.