P0420 code

dmarrs1

New member
Joined
Oct 10, 2018
Messages
4
Reaction score
1
Points
3
Location
Indiana
I had the bank 1 02 upstream sensor go out so I replaced but was quickly hit with the p0420 catalyst system efficiency below threshold. I replaced the downstream sensor but I still get the same code. I can’t believe that the converter is suddenly bad.
 
Back
Top