I don't know, but I can tell you that if a smog check technician figures out that you have an '02 or earlier cat on an '04 vehicle, your chances of passing that smog check are not good.
From
https://www.bar.ca.gov/Industry/Engine_Change_Guidelines.html ...
"Make sure the engine and emission control configuration on exhaust-controlled vehicles are certified to the year of the vehicle or newer, and to the same or a more stringent new vehicle certification standard."
"Mixing and matching emission control system components could cause problems and is generally not allowed. Engine and emission control systems must be in an engine-chassis configuration certified by the California Air Resources Board (ARB) or U.S. Environmental Protection Agency (EPA). The engine must meet or exceed the requirements for the year and class of vehicle in which it is installed."
Basically, whether there's any factual basis to it or not, the Smog Check rules say that an '04 configuration is cleaner than an '02 configuration, and they generally won't let you move to a less clean emissions configuration. You can always go to a Smog Check referee and hope for the best, but they'd be well within their rights to tell you to go get an '04 (or newer) cat.