K&N makes special performance air filters and stock replacements. The idea behind K&N is that the oiled material of which the filter is made breathes better than standard paper filters, allowing your engine more oxygen and therefore boosting horsepower. Instead of replacing these filters, as you would a standard air filter, K&N filters can be cleaned and re-oiled using their cleaning kit. Although K&N claims that filters normally will need cleaning only every 50,000 miles, special setups, such as cold air intake, may need cleaning more frequently.

Cleaning the filter: Remove the filter from the car and inspect it. If the filter is dirty, tap it gently to get rid of loose particles. Then spray the filter with the cleaner provided in the kit, and let it sit for ten or fifteen minutes before rinsing. The best way to rinse is to stick the hose or faucet into the middle of the filter, washing the dirt back out the way it came so that it doesn’t become embedded in the filter. Repeat with the cleaner if the filter still appears to be dirty. Once the filter is clean, let it sit for a while to air dry.

Re-oiling the filter: The oil is necessary in order to allow the smooth flow of oxygen while still providing protection from airborne contaminants. Using the oil can provided in the recharge kit, spray in a smooth up-and-down motion along each pleat. Let the filter sit for a few moments so that the oil may dry, and then check for white (unoiled) spots in the filter material. Touch up with the oil as necessary.

For more information about K&N filters, check out the K&N website.