I really need to find out ASAP whether I need a California Emissions y-pipe or a federal emissions y-pipe. Is there a way to find out from just looking under the car?

I just peeked under the car and was looking for some "wires" somewhere but couldn't find anything. If there are any pics, or advice someone can give me so I can clearly find out whether I need a cali emissions ypipe or not, I'd really appreciate it.

Thanks,
Dan