Sometimes it takes two stacked.

Good to know if I ever ditch the Gernby/Urge exhaust. Right now I just swap the mid-pipe out every 2 years for smog. I love this state, but sometimes it's really dumb; relocating the cat makes it non-compliant despite passing at the sniffer :LOL:

That's what I have done. But like James mentioned, the secondary O2 sensor CEL can't be triggered or it'll fail. Mine is disabled in Flashpro. Luckily my car doesn't throw the CEL when I enable it just to smog it and then I just disable it again after inspection. Sniffer isn't even part of the test anymore.

FWIW, I have or had a Berk HFC on both my S2000's, no CEL on either of the 02 sensors. I do double stack the extenders though.

My '06 + Berk HFC has yet to throw a code or CEL in the 3 years it's been on the car. Just a sample of one (1).

-- Chuck

Do you need to have stock heatshields on the HFC to pass smog in CA?

Not if they don't look, but if they see a cat that does not look like a stock one they should investigate further. My nephew works for BAR and one of his jobs is taking sting cars to SMOG stations to see if they do their job correctly. If they fail it could cost them their business and could face one hell of a fine.

ROD

I put my heatshields on to make it look like an OEM cat. The tech sees the heatshields during visual and thinks it's a regular cat. Just a HFC will fail visual inspection if it's a legit smog station.

I had the OEM headshield fitted to my Berk HFC but Ohio smog is done via the ODB2 port and there are self-service stations where there's not a soul around in the evening. Results get entered in the Big Computer in Columbus and the kiosk prints out a certificate. Never had it sniffed nor anyone look under the car. Car was registered in a non-smog county (we owned two houses) so the test wasn't necessary but I did it twice out of curiosity. A rock broke the brackets off the cat I'd welded on to hold the heat shield and I never bothered to put it back on. My part of Virginia doesn't require a smog test but the car has passed two annual Virginia safety inspections and no one said anything about it being off. Worn out windshield wipers caused great concern. :)

-- Chuck