Did you try going to smog yet? I see this question a lot and people just don't go and try.
Is it just the Mishimoto induction tube or do you have the full intake? If you just have the tube and if you are afraid of failing, put the stock tube back on.
The only CARB EO# I could find was for the full Mishimoto intake kit, not just the tube itself, which I can't imagine would do anything at all other than look good.
http://ww2.arb.ca.gov/sites/default/...eo/d-759-3.pdf
https://www.mishimoto.com/subaru-brz...take-2013.html
Maybe you can fool them and give them that #
By the way, you guys can check parts on CARB's website and find an EO#
https://ww3.arb.ca.gov/msprog/afterm...es/amquery.php