Sorry to resurrect an old thread, but I think I found out the hard way...
I would've sworn that the Vibe I bought from a dealer in West Virginia was Federal emissions. I even had the federal cat installed.
Nine months later, on a really cold day and a short trip, she threw a CEL: P0420
Brought it in thinking that she was just running rich and causing the cat to overheat.
Mechanic says it running great and can't find anything wrong.
Guess I'll run it until it starts rattling...
Seems the AWD cats are hard to find, so the next one may be a universal with California emissions.