This post is really just so people know there is a huge difference between 49 state Cats and 50 state CARB cats. My Rado passed Smog two years ago just fine with a NOS cat from my shop's parts supplier. I measured at 710ppm and the max allowed was 800ppm. Fast forward two years and California has lowered the acceptable numbers again, down to under 600ppm for NOX. I failed, this led me on the warpath to make the Corrado pass without replacing the cat. I tuned the car to a running state that was cleaner than it was when purchased new. Still not good enough. The fix, a CARB legal pre-OBDII catalytic converter. My NOX dropped from 710ppm to 3ppm. HELLO! Now I can finally start the body work on this car and lay some fresh coats of Nugget Yellow.