Last reported case: 1 months ago
Based on 5 owner reports (1 from Reddit, 4 from forums)
What is P0420?
P0420 indicates your catalytic converter is not cleaning exhaust gases effectively, typically triggered by a failing converter or upstream engine issues. This powertrain code is moderately serious and can affect emissions and performance, with Honda vehicles like the Accord and CR-V appearing most frequently in reports. Based on 975 repair cases, the average repair cost is $3847, ranging from $0 to $4700.
Common Causes:
- Failing catalytic converter (most common cause based on code definition)
- Upstream oxygen sensor malfunction
- Exhaust leaks before the catalytic converter
- Engine misfires or rich/lean fuel mixture affecting converter efficiency
Symptoms:
- Check Engine Light illuminated (primary symptom)
- Reduced fuel economy reported by some owners
- Possible lack of power during acceleration
- No noticeable symptoms in some cases beyond the warning light
🚗P0420 on 2013 HONDA Accord
This page focuses specifically on P0420 issues reported by 2013 HONDA Accord owners. The experiences and fixes below are from real owners of this exact vehicle.
Symptoms Reported by 2013 HONDA Accord Owners:
Parts Often Involved:
What Owners Say
Real experiences from 2013 HONDA Accord owners
“Every shop told me it definitely will not fix anything and that the catalytic converter is the only problem. They all quoted me around 1500 dollars, which is almost what the whole car is worth.”View original
“Since I am not a car person, I am not sure what to do. I would rather try a 50 or 60 dollar sensor before dumping that much money into such a high mileage car if there is even a small chance it could help.”View original
“Here’s the situation: I’m located in California , so I want it to be CARB-compliant. A new OEM catalytic converter from the Honda dealership is $1650 , which is painful.”View original
“I’d appreciate any guidance, suggestions, or experiences you all have had. This K24W has been solid and I’d like to keep it running smooth without dropping $1600+ unless I really have to.”View original
“2013 Accord 2.4l : P0420 can someone help explain this to me and how do I fix it? P0420 code can someone help explain this to me and how do I fix this”View original
“I have a 2013 accord which i really like. 120k. I have had the o2 sensors changed twice because after awhile it throws the code which is for the o2 sensor and the mechanic changes it.”View original
“I have had the o2 sensors changed twice because after awhile it throws the code which is for the o2 sensor and the mechanic changes it. Have had the spark plugs changed.”View original
“I have Honda Accord LX 2013 124K miles on it. I have a check light with Code P0420.”View original
“Code P0420 Catalyst Efficiency (Bank 1) I have Honda Accord LX 2013 124K miles on it.”View original
These are real experiences shared by 2013 HONDA Accord owners on automotive forums and communities. Results may vary based on vehicle condition and repair quality.
About This Data
This page aggregates 5 discussions about P0420 from 2013 HONDA Accord owners across automotive communities.
Success rate (20%) is calculated from posts where owners confirmed whether their fix resolved the issue.
Last updated: 1/12/2026