Never, ever, ever, ever, ever go to the smog referee with and non-CARB approved equipment. They are experts in spotting such things and will ding you, just as with what happened with Black Shadow. He went in because he was cited for some minor stuff, but the smog ref dinged him further as there are "illegal" modifications done to the emissions equipment.

Black Shadow -- bascially, you are screwed. You will need to remove the equipment now, and there may be a record of what you had on the car and had to remove. So if you get caught again with those parts, you may get royally screwed with serious fines (emissions fines can be up to $10,000). Since they told you to take them off, and they catch you with them back on, be prepared to pay some hefty fine. It may not be $10k, but I would not be surprised if it is in the $1,000s.

Anyhow, in other circumstances, the only way to prove the equipment is smog legal is to provide the referee with an EO number, which is an exemption number issued by CARB to the part's manufacturer, for that particular part as used in a particular model/year vehicle. Here is a link to a searchable EO database:

http://www.arb.ca.gov/msprog/aftermk...es/amquery.php

Note that HKS has gotten its boost controllers approved for many vehicles.