I would say that CA emission laws are (too) strict, but the greater LA area is still an amazing place to live. And they had to do something or the air quality would eventually make the area uninhabitable.
i know people running O/R x's, catted X's, etc etc, and have yet to have any problems. i'll be running catted H with mid length headers pretty soon and i dont expect to have any issues with the CHP nazis.
I've been running a magnaflow catted x for a couple of years now, with no problems. My car went right through smog last year (ran clean enough to pass the dyno test). I just bs'ed with the tech while he smoged it. He never even checked the cats
Yes it true, my bro has a catless Supra and he almost bit the big one on that. As for Cali stangs it can be tricky, but in the bay area where i live it's not too bad. I run a high flow two cat SLP x-pipe and it looks semi stock as far as cats go although being far from. What might do me in it after my mid pipe all i have it a small magnafolw resonator then a short 45 degree angle pipe exiting before my back wheel on the sides so it's ****ing loud. As long as you dont wrap the engine around town you'll be fine they really just crack down on imports domestics they have some respect for i guess.
Cliff notes: 10k fine-quite possible, lI live in cali, don't have leagle exhaust, really loud, i do fine. Buy some high-flows