[2horseowner]

How often do these things need cleaning? I've always used the throw away kind. Do you just wash them out and buy the re-oiling kit from K&N? I'm tempted just to buy a replacement filter to prevent MAF problems from the re-oiling.

[stlwagon]

Get the kit and clean as directed using the spray cleaner. Let dry completely. When re-oiling just make sure you coat it evenly and don't over-oil. When done, let it sit on some newspapers for awhile so any excess drips off. Most the the MAF issues result from over-oiling.

[Snake Pliskin]

To answer your original question, there is no time frame on when to clean. It depends on how dirty you get it. If you drive in a dusty area, you will need to clean more often. Even dirty these things will flow better than a clean factory filter.

[stlwagon]

Theoretically (best case) these things can go 30-50,000 miles between cleanings. K&N recommends they be checked annually under normal conditions.