Last reported case: 1 years ago
Based on 4 owner reports, 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 2010 JEEP Liberty
This page focuses specifically on P0420 issues reported by 2010 JEEP Liberty owners. The experiences and fixes below are from real owners of this exact vehicle.
Symptoms Reported by 2010 JEEP Liberty Owners:
Parts Often Involved:
What Owners Say
Real experiences from 2010 JEEP Liberty owners
“After watching many Youtube videos on fuel additives/injector cleaners this week, I thought well maybe its time. Many different sites discussed Berrymans B12 cleaner, its at Wal-Mart for just $6 a can.”View original
“Many different sites discussed Berrymans B12 cleaner, its at Wal-Mart for just $6 a can. Some swore by it and said theyve been adding it to their fuel for decades.”View original
“Bought a 2001 tundra 2 weeks ago 170k miles.... got a code P0420 yesterday & looking for some tips. I will be installing a new downstream o2 sensor tonight ( checked both upstream & downstream ) & the downstream was covered in soot so i took the liberty of replacing it.”View original
“I will be installing a new downstream o2 sensor tonight ( checked both upstream & downstream ) & the downstream was covered in soot so i took the liberty of replacing it.”View original
“P0420 Driver Side Catalytic Converter Efficiency Fix I had to disconnect the driver side cat and crossover exhaust pipe (one piece on 2003 Liberty's after 2/2/2003) to change the transmission.”View original
“I had to disconnect the driver side cat and crossover exhaust pipe (one piece on 2003 Liberty's after 2/2/2003) to change the transmission. I re-installed the original starter with 173k miles when re-assembling the vehicle.”View original
“code p0420 then code p0138 i have a liberty 2002 automatic 4x4 3.7 liters having problems first with the p0420 have read in the internet that the spark plug fouler while solve this put it like they said then a few miles later the mil came back again now with the code p0138 hope someone may help thanks in advance”View original
“i have a liberty 2002 automatic 4x4 3.7 liters having problems first with the p0420 have read in the internet that the spark plug fouler while solve this put it like they said then a few miles later the mil came back again now with the code p0138 hope someone may help thanks in advance”View original
These are real experiences shared by 2010 JEEP Liberty owners on automotive forums and communities. Results may vary based on vehicle condition and repair quality.
About This Data
This page aggregates 4 discussions about P0420 from 2010 JEEP Liberty owners across automotive communities.
Success rate (50%) is calculated from posts where owners confirmed whether their fix resolved the issue.
Last updated: 9/23/2024