I just bought a 2014 QX80 and it had the check engine light. I scanned the OBDII port and I got P0420 and P0430 codes. My shop here in Texas wanted to charge me $4,600 to replace the cats. I was freaking out fearing the cost of the repair and fearing the engine sucking in the catalyst substrate; grenading the engine. I saw the engine was not misfiring nor was I losing power/performance.
I decided to look into YouTube and found a product called CataClean. I bought 2 bottles of it and added it to a half tank of gas. I drove 40 miles. Then I revved the engine to 5k and kept it there for 2 minutes. I cleared the codes and the check engine light has not come back. I checked the voltage of the O2 sensors at 3k rpm and they are functioning as expected. This product is amazing!!! I'm gonna use it every 3 months to keep my cats free-flowing.
Has anyone else had these codes? Have you tried CataClean? Did it work for you?