K&N BMW Drop In Air Filter

SKU: 33-2231 | UPC: 024844092304

K&N 33-2231 Replacement Air Filter for 1999-2006 BMW 3 Series M3 X3

K&N 33-2231 is a washable reusable high-flow drop-in air filter designed for select BMW models from 1999 to 2006. It features layered oiled cotton media that improves airflow for more horsepower and acceleration while trapping contaminants. This direct factory replacement installs in minutes and lasts the life of your vehicle.

Key Features

• 4 Layers of Protection: Multiple layers of premium cotton gauze with tacking agent create mesh to block and trap harmful contaminants
• Clean Once Every 5 Years: Needs cleaning every 75000 miles under normal highway driving or 5 years at 15000 miles per year
• Easy Installation: Pre-oiled and ready to drop into factory air box for quick performance gains with no tools required
• Engineered Power: State-of-the-art media increases horsepower acceleration and overall engine performance
• Saves Money: Reusable design saves up to $125 versus multiple disposable filters over 200000 miles

Product Notes

• Washable and reusable backed by K&N No-Hassle Lifetime Limited Warranty
• Reduces landfill waste from over 200 million disposable filters yearly
• Rugged construction with premium materials lasts vehicle lifetime

Installation Notes

• Professional installation recommended.
• Drops directly into OEM air box no modifications needed
• Pre-oiled and sealed for immediate use

This Part Fits

Year	Make	Model	Submodel
1999	BMW	318ti	Base
2000	BMW	323Ci	Base
1999-2000	BMW	323i	Base
2001-2006	BMW	325Ci	Base
2001-2005	BMW	325i	Base
2001-2005	BMW	325xi	Base
2000	BMW	328Ci	Base
2000	BMW	328i	Base
2001-2006	BMW	330Ci	Base
2001-2005	BMW	330i	Base
2001-2006	BMW	M3	Base
2004-2005	BMW	X3	2.5i
2004-2006	BMW	X3	3.0i

Why Choose K&N?

• Proven in motorsports and street performance for decades
• High-flow cotton gauze media delivers more air with full protection
• Precision engineered for exact OEM fit and long-term reliability

Frequently Asked Questions

• Q: Does K&N 33-2231 fit 2003 BMW 325i?
  A: Yes it fits 2001-2005 BMW 325i Base and other listed E46 models directly into factory air box
• Q: What material is used in this filter?
  A: 8-layer oiled cotton gauze panel filter 8.5 in wide 11.125 in long 1.313 in height
• Q: What is the warranty on this air filter?
  A: No-Hassle Lifetime Limited Warranty covers stock replacement filters with limitations apply

Shipping &amp. Handling

• Method: Standard Ground
• Availability: In stock – ships same or next business day
• Packaging: Protective box 12.25 x 11.75 x 2.75 inches
• Weight: 1.3 lbs