Automotive air filters have to be cleaned regularly to maintain the quality of their performance and to prevent building up of dust and clogging the cabin vents. It’s also important to remember how clean the air-filters properly so they won’t be ruined.First of all, be careful in removing it from the car to not spread the dust buildup in it and to be able to clean it more easily. Place it carefully on the floor, then spray your cleaner on both sides of the filter. The K & N Air Filter Cleaner comes in a kit already so if it’s your first time clean it, you won’t have a problem about what to use and how. After you’ve sprayed both sides with the cleaner, leave it for about 10 minutes so the filter can absorb the cleaner and for it to loosen the dirt on the cleaner. However, don’t let it dry in the cleaner.After 10 minutes, rinse the cleaner off the automotive air-filter. It’s recommended to use a cool water and a low-pressure one. If you’re using a hose, flush the water from the clean side of the air-filter up and down until all traces of dirt and cleaner are gone. If there are still portions of dirt visible in any part of the filter, you can repeat the process of cleaning.After rinsing the filter and making sure there aren’t traces of either cleaner or dirt in it, tap it gently to remove the excess water then let it dry naturally. It’s important to make sure that it’s completely dry before proceeding to the next step. When the filter is already completely dry, it’s time to oil it. Remember to apply the oil only on the dirty side of the filter. The K & N Cleaner comes in two containers, the spray bottle and the squeeze bottle. If you’re using the squeeze bottle apply the oil along the crest of the pleats. If you’re using a spray bottle, make sure you spray an equal amount along the pleats of the filter. Leave it for 20 minutes, and make sure that the color is even on the entire dirty side of the filter.Before putting back the automotive air-filter, do a last inspection about the color of the filter and if there are any damages present. If everything looks right, follow the installation instructions that came with the kit when you bought your automotive air filter.