Not sure which 2004 Mercury Mountaineer Air Filters are right for you? We have over 14810 customer reviews, with an average rating of 4.5, to help you find exactly what you're looking for. Here's what some of our customers have said:
"This is the seventh K&N filter I've purchased for my cars through the years, and they never fail to perform. Increased mileage, some more power, and never having to buy another air filter (unless you buy new cars a lot like me!).
You can't go wrong!!!" —Ryan T from Cheyenne, WY bought a K&N Air Filters for a 2004 Mercury Mountaineer.