Intake Carbon Filter: Worth Removing?
 

I have an HKS replacement air filter on the way, and am trying to decide whether it's worth the trouble to remove the carbon filter that comes standard on the USDM airboxs. Wondering if there's any true benefit to doing this since I'll be working on the area anyway to install the replacement filter. Would make it a quick removal.

A few folks joked about this adding some power or throttle response, but how much of that is just blowing smoke?
Anyone actually have any dyno data that would show there is any difference?
Does this introduce any reliability concerns?

That carbon filter is a HC adsorption filter. Its purpose is to adsorb fuel evaporation gas that accumulates in the intake system while the engine is stopped, and prevents it from being discharged into the atmosphere.

This is what I've heard as well; it's essentially emissions related right?
That said, there seems to be varying opinions on whether or not this is hampering airflow in-take to any degree.

Would removing an HC adsorption element lead to any increase on engine wear, or is this strictly to prevent atmospheric discharge as you said?

What I posted came directly from a Subaru document.

So little benefit why mess with emissions. It’s not worth it.

https://www.youtube.com/watch?v=fDVX...VprPU&index=17


This will be my 4th mod after seat chime,fake engine noise and kill the hill holder.