I have a 2005 accord sedan 3.0 v6 w/ 397,000 miles and recently had the cel indicator pop up. I pulled the following codes; p0420, 61-1, 68-1 and 83-1. My charging system checks out good as well as the battery and there is no power loss. I took the car to two mechanics and one stated o2 sensor bank 1 and the other told me all collectors and cats need to be replaced. I have reset the codes and after 30 miles I have the p0420 in pending codes. Any suggestion?

 

https://www.hondaaccordforum.com/for...es-v6-cats.jpg

It probably is the cat needing replacement. P0420 on your 2005 Accord V6 is the rear warm up three way cat (TWC) (Bank 1)

 

Thanks Redbull-1, I will take it to another muffler shop to confirm. I would think that if all needed to be replaced I would notice performance issues, which I am not.