If it was purchased new in San Diego it *should* be a CA
version, but meeting "federal EPA" standards doesn't sound
like it.

The CA models had an O2 sensor while the other 49 states
did not.  The exhaust system is different because of this.
The 49-state version fed the two exhausts into a "cross-over"
pipe that made a U turn to the cat and the muffler.

The CA version fed to a cat on the drivers side, with an
O2 sensor, then rearward to the muffler.

If you have a Bentley, it is much clearer there.

Richard