2007 Honda Accord LX AT 2.4L with engine code P0420

Question

P0420: Dealer recommended replacing "Converter Bank 1: catalytic converter, sensor, and all shields" for $1,150. All necessary?

Car has 113,000 miles.

Answer 1

P0420 Catalyst system below threhold

Catalytic codes are not always caused by a worn catalytic. There is a known problem with this code for a Honda Accord  . The TSB for this is TSB 12-052 Engine control Mil on / DTC P420 set. What this TSB is about is a probable cause that the ECM software may misinterpret sensor input as a deteriated catalytic convertor. Most cases are ECM software

Answer 2

P0420 Honda Code - Catalyst System Efficiency Below Threshold Bank 1
Read more: https://www.autocodes.com/p0420_honda.html