Somewhat related... I used to think the whole "smog" thing was overrated until I visited some family in California a month or so ago. Holy Cow! You guys DO have some serious smog issues.
Haven't been on in ages but my advice is to go to a different shop if you haven't already.
any changes after the factory cats do not have anything to do with smog. the only one that can hassle you about mufflers would be a cop for noise reasons.
on my truck I have headers with an EO number, factory cats and then everything else has been replaced and the smog shops do not care since the cats are there in the factory locations.