Emissions code P0420

[Jenkin121]

My car has been giving me this code for quite a while and I was wondering if anyone on here can help me. The scanner says that the code means the cat is bad, but I've checked the cat and it seems to be in good shape. Now I am by no means a mechanic...so my diagnosis could be wrong, but if anyone has any ideas I would appreciate it. Pretty soon I'm going to do this :bang: to my car. Thanks for your help!

[Smaay]

how are you checking if your CAT is in good shape. its not like you can open it up and check it out. chances are it did go bad. you need to have a replacement ODBII CAT welded back in your exhaust pipe

[Jenkin121]

I cut the cat out and looked at it and there wasn't a clog or any damage on the inside...and I know that the cat was replaced shortly before I purchased the car last June...so it was just a guess.