I have a Jim C intake with the ITG filter. I was cleaning my throttle body. When I was taking the intake pipe and the air mass sensor off I noticed as I was cleaning the inside of the tubes that is was dirty. I know that it is not going to be spotless in there, but it was too dirty. So I cleaned everything and put it all back together. I ordered a K&N cone filter to fit it. Since I installed the new K&n filter I have check the inside of the intake tubes. It has been about 3 weeks since I changed to K&N. The inside intake tube is spotless. Yes the ITG filter was oiled right. I do not live in a dusty area. Just my .02.