Yep, when I had my L28ET in my 74' 260Z I was able to pass smog. I detuned it to run ultra clean and placed some of the original equipment on it for the test only to get my smog exemption. I had to walk them through the whole thing. They thought my glass packs were cats and wanted to fail me, then they failed me for not having the proper inlet on the fuel filler. I called CARB on the spot and stated what I had, he agreed I was legal. Next, I told the referee who had just failed me 10 minutes earlier. He walked away and I thought that was it. A minute later he came back with an exemption sicker and I was on my way. Gotta love it.