The K&N 33-2359 is a red panel replacement engine air filter built on the manufacturer's layered, oiled cotton media. K&N's design uses 4 to 6 layers of cotton gauze sandwiched between two aluminum wire screens. Because the element is washable and reusable, you can clean and re-oil it rather than replacing a disposable paper filter at each service. The manufacturer says it is designed for high airflow while maintaining filtration.
Paper media traps dirt only on its surface, so airflow drops as it clogs. The manufacturer says the layered cotton design keeps airflow up even as the filter gets dirty. The manufacturer also states the element is designed to boost horsepower, but it does not publish a gain figure for this part, so this is a filtration and airflow upgrade rather than a guaranteed power number. Shoppers searching for a 2007 2008 Honda Fit 1.5L washable intake filter, a Honda Fit 1.5L L4 cotton gauze air filter, or a K&N 33-2359 drop-in replacement will find this model matches the factory airbox footprint.
The manufacturer states that the 33-2359 was designed for 2007 and 2008 Honda Fit models. Its 2009 through 2013 Fit filter is a different part, the 33-2422. Confirm your model year before ordering.
The manufacturer describes the element as washable and reusable and lists a re-oiling amount of 0.58 oz (17 ml). Cleaning interval details vary across sources, so confirm the recommended service schedule with the manufacturer's instruction sheet.
Owners on user forums report that a filter installed upside down can make the airbox lid difficult to seat. Check the filter's orientation against the housing before closing it up.
This is a drop-in swap. The manufacturer notes the filter arrives pre-oiled and fits into the factory airbox without modification. Owners on user forums describe the airbox as a multi-chamber black plastic housing at the left front of the engine bay, held down by two metal clips at the front and a wire spring clip on each side. Release the clips, lift the lid, remove the old element, and note its orientation before seating the K&N. Expect some effort freeing the lid, especially if the filter is misseated. The manufacturer's installation sheet should be checked for any tool requirements or install time, which were not confirmed in this research.
