Rich, I am dealing with this as well. It was a complete surprise to me when I received the non CARB compliant back from DMV.
So did you say that you did go through the arb.ca.gov/cleantruckercheck site and register your RV and received clearance or your CA registration? What year is your engine? Or, did you register it out of state?
I have also read through much of the jargon on a few different sites and from what I understand RVs are exempt. Rvs registered out of state can visit CA unrestricted. RVs registered in CA must register through the above site but must then have a Clean Truck CARB check, or something like that, annually. Interestingly, I can not seem to even find a single one of these places that perform these test to try to get more info. Not sure they even exist yet.
Check out the attachment. From what I understand, if you are not exempt this is what you are dealing with. In CA no mater where your vehicle is register, if you have and engine from 2010 or earlier it needs to be replaced.
I also read that when registering your RV on the ca.gov site that you need to put in, not only, a s... load of info, but photos of the inside of the coach to proof its a recreational vehical?
Thanks for your feed back