When I bought my "Certified Pre-owned" civic, the dealer had changed the oil/filter, air filter, and cabin air filter since the car had 13,000 miles on it.
I pulled out the air filter the other day to look at it. It is made by Filtech (same that make some of the OEM Honda oil filters). It has a greenish blue coating on the "air in" side and regular white paper on the "air out" side.
I need to pull it back out and see if I can scratch any of this material off? I didn't think anything of it until I read this post. Thanks. It looks like Wix for me from now on.
Brian