2002 Camry California Spec. P0420

[my_blue223]

I have a P0420 code showing up for my camry. It's a 2002 2.4L California spec. So I've heard, I'm dealing with a car that has a more efficient emissions system because it's Calif. spec. My main issue is that my car is a 4 cylinder and it burns gas like a V12 engine. I considered a few options, and for those who don't know, the dealership would be the best techs to determine what exactly the P0420 means. Most autoshops and mechanics will tell you a list of possible things. "doorman68" posted that list on a seperate thread. Toyota will confirm which of the six issues are what you're faced with. Mine is definatley a bad Bank 1 cat. But, I have some options and I need some help.
Options:
1. Delete the cat and buy new headers connect it to the factory exhaust. (least $$)
2. Buy a new OEM cat and install it myself. (Approx. $450)
3. Buy a new and complete exhaust system. The headers to the exhaust. (most $$$)
I'm curious to find out what would happen if I do delete the cat. I heard deleting a cat. causes you to have high end power and that it might drop your MPG. And I heard the same goes for changing your exhaust system. I also heard something along the lines of, "If you delete the cat. you would have to add a back cat." I dunno if any of these things are true. HELP!