Another k&n thread awesome.
Nothing wrong with a k&n drop in filter if you are concerned with the fine particals they make a fine mesh screen.
Another great filter is the AEM dry flow filter.
And if you really want buy a air intake kit from volant they have a option to use a Donaldson air filter.
On my current truck of 3 years with a k&n intake never once had a mass air flow sensor covered in oil. And both the intake tube and the t/b were clean. And yes I used white paper towel to clean the inside of the air intake it came out clean.
Will it add gas milage maybe.
Performance it will add some hp.
But if you know how computers work cars are the same. When installing a new filter or intake disconnect the battery for a bit then reconnect and start it up the cars computer will now relearn the new air flow and correct the fuel tables as you drive.
But someone will jump on hear and tell you you don't need to disconnect the battery. Well let me help you out you are wrong.