I used to live in CA, I now live in AZ, but I remember the tests there all too well. They're not too much better here.
Your best bet for info is the BAR web site:
http://www.smogcheck.ca.gov/stdhome.asp
Tons of info here, too much, in fact. And a real PITA to find simple charts with the limits for CO, HC, and NOx by year. I couldn't find them, but the data I did find indicated to me that even if there isn't a standard for it, they do measure NOx and record the data, regardless of year.
They also have a history feature that lets you see the smog history of your car. Looks like it only dates back to the beginning of SMOGII, as my car's records aren't there.