Anyone remove the Hydrocarbon Filter

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Jul 3, 2008
Illinois and Alaska
Has anyone done this? I was looking inside the intake today and noticed this secondary air filter. Looked it up and found it was an HCF used to prevent fumes from escaping the engine after turning it off. However, that is a non issue because the fuel injectors turn off to shut the engine down on modern EFI cars.

I have heard good things such as increased throttle response and better mpg - just throwing it out there.
How would you get better fuel economy from removing it ?

A picture or diagram showing it would be helpful.
Better airflow... I have a CAI on my BMW and get noticeably better highway gas mileage. Low 30's where the car was rated at 28 MPG highway by the old standards. I think my city mileage is lower though because I can't resist running the revs up for the intake growl :D
I say pull it off, drive a few tanks. And see if there are any improvements.

Soooo. I expect to hear you took it off :) ! And are measuring changes and throttle response.

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