2014 Ford Edge Limited Catalytic Converter.

[Lucho80]

Hi. My edge has the P0420. I replaced all the O2 sensors. The car runs just fine, but I have this code. Check engine light is on. I am about to order the 2 catalytic converter, but before I spending that money (about $2500) I was hoping to ask if there is something that I con do before I replace them. I live in the "cleanest state in USA" (Sarcasm), my car has 234K miles an running. I was reading that the catalytic converter should last the car's live long, so if they need to be replaced, that means that there is an issue on the turning? It has new spark plugs, car runs good like always... not sure what should I inspect before I get the Cats. Thank you in advance for any help. If you know a good/cheap place to get these parts, please, let me know as well. Thank you!