The paper air cleaner element is a good idea—it’s why it’s been in use for better than 50 years. However, in the quest for improvement, some OEMs have looked beyond it. Certain 2005-2007 Ford Focus vehicles were fitted with an unconventional air filtration system. The airbox in these vehicles has filtration media made integrally—there’s no separate filter to remove. It integrates a carbon arrestor and the assembly has a restriction gauge on it, like the one you’ve seen on many diesel airboxes. The air cleaner has internal baffling and uses multiple layers of foam designed to filter air progressively, and the housing is sealed.

Ford calls this a lifetime assembly. But like most items claiming to never require service, eventually the need crops up. The filtration media can and does eventually clog and lose its ability to filter the incoming air charge, especially when the vehicle is operated in dusty or dirty conditions. It’s not uncommon to have one of these roll into a bay with complaints of rough idle and poor fuel economy. To add insult to injury, the restriction gauge will often fail to register any problems with obviously plugged assemblies.

To us, it seemed like an obvious improvement: improve serviceability, lower the cost.

Ford did sell a replacement, but it was only available as a complete assembly costing several hundred dollars. It too featured that same high-tech (but unserviceable) foam filtration media. Note the previous sentences were written in the past tense—the assembly has since been discontinued.

AS810002PR

Air Cleaner Assembly

258-519: Ford Focus 2007-05

These vehicles are still on the road, and many of them are at the point where the air cleaners need attention. Our OE FIX 258-519 is just the ticket. It’s a complete air box that bolts right in place of the OEM unit. The difference is we designed ours to use a replaceable filter that’s served well for many years. We chose not to use a bespoke element. Instead, it’s designed around an existing paper air filter. Should you install our airbox (or be tasked with servicing a car that’s already had our airbox installed), the air filter for a 1991-1994 Saturn SL will drop right in.

To us, this was an obvious improvement, allowing us to improve serviceability, lower cost, and provide access to inexpensive, high-quality aftermarket air filters. Hopefully you agree with our assessment of this part: it’s a breath of fresh air.