My apologies if the following has already been discussed...
I've been curious about what modifications are legal in California in regards to emission standards. I've heard some different opinions regarding things like the JWT Pop Charger, the Stillen High Flow Air Intake System, and of course... headers.
The following site lists the manufacturers of various after-market parts, and their corresponding executive orders deeming them legal in California.
For example, an executive order search by device found that the Stillen I just purchased for my 92 Infiniti G20 is in fact CARB certified for my model & year with this executive order.
Sadly, I was not able to locate Executive Orders for legal headers for the SR20's regardless of year/make/model.
Again, I'm sure many of you already know this, but I thought it was helpful. Especially to see if a CARB certified modification was legal for my specific model & year. I suspect it may also be helpful for those of us who are seeking manufacturers that provide other compliant products for our specific year/model.
Also, In speaking with the smog test guy down the street, he indicated that even if your car passes smog, you may fail the visual inspection if you have obvious modifications such as a header. If they don't see the CARB tag, you'll get red-flagged, at which point you have to deal with a smog referee. Sounds about as much fun as a barium enema.
You'd figure that it wouldn't make any difference what the #$@# you put on your car so long as it passes the smog check, but alas, this is California. Go figure.
Until next time, I am... and will remain...