Definitely recommend the K&N filter for "sound reasons" : r/FordFocus
ETS Ford Focus Air Filter
K&N Cold Air Intake Kit: High Performance, Guaranteed to Increase Horsepower: 2013-2018 FORD (Focus ST) 69-3518TS - Walmart.com
13-18 Focus ST 2.0L K&N Replacement Air Filter
Lifetime Air Filters: Fad Or Future?
Car Engine Air Filter for 2012 ford focus 1.6L 2.0L 2013 Ford ESCAPE 1.6T 2.0T / C-Max Kuga AV61-9601-AD - AliExpress Automobiles & Motorcycles
Replacement Air Filter
OE Replacement for 2007-2018 Ford Focus Air Filter (RS / S / SE / SEL / ST / Titanium) - Walmart.com
7159 Green Filter High Performance Cylindrical Air Filter Green Color – FSWERKS
K&N Replacement Air Filter Focus RS mk3
K&N Ford Ranger 2.3L Drop In Panel Air Filter (19-22) 33-3086
Amazon.com: K&N Engine Air Filter: High Performance Premium Washable Replacement Car Air Filter: Compatible 2007-2019 Ford/Lincoln/Volvo (C-Max, Escape, Grand, Kuga, Focus, Tourneo, MKC, V40, V70, C30, S40)E-2993 : Automotive
2012-2018 Ford Focus Engine Air Filter Check ST 2.0L 4 Cyl. Turbo
What Is A Cabin Air Filter And Why Is It Important? | FordPartsOnSale Blog | FordPartsOnSale.com
Installing a K&N High Flow Air Filter on my 2016 Ford Focus ST - YouTube
Ford Focus Mk3 K&N 57I Cone Air Filter - Focus Mk3 1.0 EcoBoost - Filters - Panel - Pumaspeed Milltek Ford Performance Tuning Milltek Sport Exhaust Ford Fiesta Focus ST RS Parts Specialist
2008 Ford Focus Cabin Air Filter Outlet, 54% OFF | www.ingeniovirtual.com