Hey my CEL came on about a couple of days ago. I had it checked out at the local part store and it came back with code p420. I recently had my cat replace and the egr valve port clean. I guess I am wondering if the cat is gone bad again? (do i have two or one cat converter) or could it be the o2 cesnsor?

 

A link for you;
https://www.hondaaccordforum.com/Hel...m_46133/tm.htm

 

or this...

https://www.hondaaccordforum.com/Mem...m_43513/tm.htm