Many people have been worried about the effectiveness of the simota intake filter. I am taking my car into the dealer tomorrow so I took the imy simota intake out and checked the inside of the filter. I have been driving through a constuction zone, that is more like off roading with all the dust that flies around, for about 6 months. You can imagine what this does to a filter. The outside of my filter is filthy see pic 1 but the inside is clean see pic 2. The maf housing was completely clean as well so I think it is safe to say the filter is working. I just washed off the outside of the filter with some water, let it dry and I am ready to put it back in. No oil.