K&N 33-2438 Engine Air Filter

The 33-2438 is a 4-layer oiled cotton gauze panel filter designed as a direct drop-in for the 5th-generation Toyota 4Runner (2010·2024, 4.0L V6), Lexus GX460 (2010·2023, 4.6L V8), and Toyota FJ Cruiser (2010·2014). K&N claims up to 99% filtration efficiency using ISO 5011 methodology (K&N's own published data; no independent third-party lab has verified it for this specific SKU). Airflow performance and horsepower claims are not independently corroborated by dyno testing for this drop-in filter application. OEM cross-reference numbers 17801-38050 and 17801-38051 appear in the product listing specifications; these have not been independently confirmed in a separate parts database as of the initial research pass. The filter ships pre-oiled and installs in under five minutes with no tools required.

Right pick for a 5th-gen 4Runner (2010·2024), GX460, or FJ Cruiser owner who wants to eliminate recurring filter replacement costs over a long ownership horizon and is comfortable with periodic cleaning maintenance using K&N's Recharger kit. Skip if your 4Runner is a 2025 or newer model on a different platform · that generation will require a different filter. Also skip if your vehicle's MAF sensor is sensitive to filter oil and you plan to re-service the filter yourself; the general K&N community guidance is to apply minimal oil and allow 20·30 minutes for penetration before reinstalling. The 33-2281 fits the 4th-gen 4Runner (2003·2009); these two filters are not interchangeable across the platform change.

Passive replacement component · no chemical exposure pathway during installation or removal; no SDS applies to the filter. The environment score of 6.9 reflects the washable reusable lifecycle: this filter eliminates 4·8 disposable filter replacement cycles over a typical 100,000-mile vehicle ownership period, with a recyclable metal frame and cotton gauze media; no K&N take-back program is currently documented. Filter cleaning and re-oiling with K&N's Recharger kit involves solvent and petroleum-based oil · review that product's safety data separately for PPE guidance.

An engine air filter only does its job if it actually fits your car, and the same vehicle often takes a different part year to year. Before you buy, find the engine air filter for your vehicle in the CarCareTruth air-filter finder · pick your year, make, and model and we'll show the filters that fit it, ranked by our independent score and cross-checked against multiple catalog fitment sources.