Cat outlet temp should be higher than inlet temp by 100 C at least. That, along with the 430 code, means cat is dead. Either replace the cat or, if the cat isnt clogged and reducing performance and MPG, spend $20 on "MIL eliminators", which look like the old spark plug antifoulers. Simply remove post cat O2, screw in the adapter, and screw the O2 into the adapter. They work.