The K&N 33-2430 is a panel-style, drop-in replacement air filter for the 2.4-liter four-cylinder Acura TSX. The manufacturer's page lists it for 2009 through 2014 TSX models with the 2.4L L4 fuel-injected engine, so it covers the 2009 and 2010 years in this listing's title. It uses layered, oiled cotton gauze media, and K&N says the panel was engineered around the factory airbox shape to achieve a proper seal. Because it is washable and reusable, it replaces the disposable paper element with a filter you clean and re-oil rather than repurchase.
The case for this filter is long-term value and filtration performance rather than dramatic power. The manufacturer says it can go up to 50,000 miles before cleaning, depending on driving conditions, and it carries a No-Hassle Lifetime Limited Warranty. Owners on user forums describe any gain as subtle, with one reporting a noticeable sense of punch in third gear while another said it added little power. Forum members also debate whether the open media trades some fine-particle filtration for airflow, so details vary and buyers should weigh that tradeoff. The manufacturer claims filtration efficiency of up to 99%.
Installation is a straight swap: remove the factory filter and seat the K&N in the existing airbox, with no cutting or adapters. The filter arrives pre-oiled. Owners on user forums say the TSX airbox uses retaining clips instead of screws, which makes a filter change quick. Keep a K&N filter care kit on hand for cleaning and re-oiling. Search terms this part matches include 2009 2010 Acura TSX 2.4L drop-in air filter, 33-2430 reusable cotton intake filter, TSX high-flow panel air filter, and washable K&N air filter for TSX.
The manufacturer lists this filter for 2009 through 2014 Acura TSX models with the 2.4L L4 engine, which includes 2009 and 2010. The 3.5L V6 TSX uses a different K&N part, so confirm your engine before ordering.
The manufacturer says the filter can go up to 50,000 miles before cleaning, depending on driving conditions. Cleaning should be done with K&N's filter care products, and the filter must be re-oiled after washing.
The manufacturer designs it as a drop-in replacement for the factory airbox. Owners on user forums report that the K&N sits slightly larger than the stock filter, so check that the airbox lid closes fully before driving.
This is an easy, tool-free DIY job. Open the airbox, remove the stock filter, and wipe out any loose debris from the housing. Set the K&N into the base so it seats fully against the sealing surface, then close the lid and secure the retaining clips. The manufacturer's install sheets for comparable K&N panel filters call for cleaning the sealing surfaces and orienting the filter so its engraving faces up, so follow the same approach here. Make sure the lid seats evenly without forcing it, since an improperly seated filter can prevent a proper seal. Owners on user forums consider the swap one of the quickest air filter changes on this car.
