PRODUCT DETAILS
AEM 25-204 Universal Inline Fuel Filter, 10 Micron, -6AN ORB
You've upgraded your fuel pump, you're running big injectors, and the last thing you want is contaminated fuel killing a $1,200 set of injectors or a high-flow pump. AEM's 25-204 inline fuel filter catches particles down to 10 microns while flowing 100 gallons per hour (roughly 340 LPH). Fine filtration, serious flow, compact enough to fit in tight spaces.
The filter installs inline between your fuel pump and fuel rail. Both the inlet and outlet are female -6AN ORB (O-ring boss) fittings, so you'll need -6AN male ORB hose ends to connect to it. ORB fittings seal with a machined O-ring groove rather than tapered threads. That's a positive, leak-free seal, which matters when you're running a high-pressure fuel system.
All sealing O-rings and gaskets are Viton. Viton handles gasoline, straight alcohol, E85, and ethanol blends without swelling or degrading. If you're running flex fuel or a dedicated E85 setup, those Viton seals are not optional; regular rubber O-rings will swell and fail over time on alcohol-based fuels.
Why 10 Micron Filtration Matters on a Built Fuel System
When you're running a high-flow pump and large-displacement injectors, small particles matter more than they do on a stock setup. High-flow pumps move a lot of fuel volume, and they move whatever contamination is sitting in your tank right along with it. Large injectors have tight tolerances. A particle that barely affects a stock injector can partially block a spray nozzle on a larger one, which means poor atomization, uneven combustion, and eventually a stuck or clogged injector.
Fuel contamination isn't just a problem for old cars with rusty tanks. Every fill-up is a potential source of sediment and water from the station's underground storage. Even clean fuel picks up debris in transit. A 10 micron filter catches what coarser filters let through, so your injectors see clean fuel every time.
Billet Aluminum Housing, Replaceable Element
The housing is machined billet aluminum. At 3.5 inches long and 1.5 inches in diameter, it's compact enough to mount in most engine bays or underbody fuel lines without major routing changes. The end caps are machined with O-ring receiver grooves for a positive seal at both ends.
The filter element is replaceable, so when it's dirty, you pull the element and swap it rather than replacing the whole filter. Check it when you're doing fuel system maintenance, and replace it sooner if fuel pressure starts dropping under load. A clogged filter will starve your engine, and on a boosted or high-compression build, that means lean conditions exactly when you don't want them.
Fuel Compatibility and CARB Status
AEM rates the 25-204 as compatible with gasoline, alcohol, and gasoline/alcohol blended fuels, including E85 and ethanol blends. The Viton seals are what make broad fuel compatibility possible.
The filter carries CARB EO Status 5, which means it's legal for sale and use on emissions-controlled vehicles, non-emissions-controlled vehicles, and racing-use-only vehicles. That covers street cars, track-only builds, and everything in between.
What to Know Before You Order
This filter uses -6AN ORB fittings on both ends. ORB (O-ring boss) is not the same as standard AN. If you're running standard -6AN hose ends without an O-ring boss, you'll need ORB-style hose ends or adapters. Check your fittings before you order so you're not waiting on adapters when you're ready to install.
This is a universal filter with no vehicle-specific fitment. It goes inline between your fuel pump and your fuel rail, and it's your responsibility to route and mount it correctly for your application. Make sure you've got clearance from heat sources and moving parts, and use proper mounting hardware so it doesn't vibrate loose.