I got two codes 0702 and 0703 and they are Three Way Catalyst (left and right bank). Any one had this problem. I am guessing it is just a bad cat but some other problems could be spark plugs,fuel injectors etc., according to this site. I have no idea how to check for the problem. Any help is appreciated!

 

Bump...bump...bump...

 

If your engine missfiring or studdering?

 

No, it seems to run fine and I am still getting my normal gas mileage.

 

Than its probably your cats. If the engine has severe missfiring, the ECU would store that code and show it to you when you do a self-diagnosis.