Last reported case: 1 weeks ago
Based on 11 owner reports (8 from Reddit, 3 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 HONDA CR-V
This page focuses specifically on P0420 issues reported by 2010 HONDA CR-V owners. The experiences and fixes below are from real owners of this exact vehicle.
Symptoms Reported by 2010 HONDA CR-V Owners:
Parts Often Involved:
What Owners Say
Real experiences from 2010 HONDA CR-V owners
“Been under the car and like I said, everything unscrews like butter as needed and no leaks. 1000 mile oil consumption is 2mm on the dipstick if that. So $6000 total.”View original
“Update on our 2010 215k CRV EXL we paid over market for: $200 later, gremlins are gone. We paid 5800 for a 215k mile car because my elderly mother has zero patience to test drive anything and the seats must be butt height.”View original
“• Engine Flush for excessive oil consumption (Got lucky it fixed the stuck rings at the expense of the first catalytic converter) • VTC screens (cam and spooler)”View original
“• Oil filter housing gasket (Major oil leak) • Engine Flush for excessive oil consumption (Got lucky it fixed the stuck rings at the expense of the first catalytic converter)”View original
“I just fixed it myself for $65. P0420 is very common with Hondas and the dealers LOVE it.”View original
“[2010 CR-V] Dealer wanted $4000 for code P0420. I just fixed it myself for $65.”View original
“ok I got this CRV pretty cheap nothing to literally goes crazy but have this two codes p0420 and p1457. The Gas cap was loose so I deleted the codes and waiting to see if it shows up again.”View original
“CRV 2003: P0420 I read the o2 sensor with a multimeter and smoke came today from under the cat converter ok I got this CRV pretty cheap nothing to literally goes crazy but have this two codes p0420 and p1457.”View original
“P0457 Evap emission sustem leak detected (gas cap loose/off) - already replaced gas cap but didn't fix issue, new filler neck ? P0442 Evap emission system leak detected(small leak)”View original
“P0420 Catalyst system efficiency below threshold P0457 Evap emission sustem leak detected (gas cap loose/off) - already replaced gas cap but didn't fix issue, new filler neck ?”View original
These are real experiences shared by 2010 HONDA CR-V owners on automotive forums and communities. Results may vary based on vehicle condition and repair quality.
About This Data
This page aggregates 11 discussions about P0420 from 2010 HONDA CR-V owners across automotive communities.
Success rate (27%) is calculated from posts where owners confirmed whether their fix resolved the issue.
Last updated: 2/23/2026