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P0420 on HONDA ACCORD

Severity
Medium
NHTSA Reports
4
Most Affected
2007, 2008, 2010

What P0420 Means on Your HONDA ACCORD

Real HONDA ACCORD Owner Reports (Source: NHTSA Complaints Database)

"I just bought the car and had it 1 week and i was driving to work when the check engine light came on suddenly and car started misfiring. this happened right when i was stopped at a light and turned on my a/c. 3 codes came on which were p0420, p0139, and p2647."

— 2007 HONDA ACCORD owner • POWER TRAIN,ENGINE • Filed 07/17/2020

"In 2008, i purchase a new honda accord v6 paid with financing $25,000. i purchase a brand new vehicle to not have to be bothered with someone else problems. when my car reached 100 thousand miles in the winter, i heard a loud knocking sound under the hood and i was loosing a lot of oil."

— 2008 HONDA ACCORD owner • POWER TRAIN,ENGINE,FUEL/PROPULSION SYSTEM • Filed 04/03/2019

"My 2010 honda accord has had a check engine light for a p0420 code at 110k miles. for someone that knows something about cars, a catalytic converter should not be going out this soon."

— 2010 HONDA ACCORD owner • ENGINE • Filed 05/13/2016

"After service at honda service station at rosenberg, tx... i had issues with the temperature sensor in the front of the grill, also a code showed up 2 days later, along with check engine light... when scanned it was "p0420"..."

— 2013 HONDA ACCORD owner • ENGINE • Filed 11/19/2019

Data from NHTSA Vehicle Complaints Database. All reports are filed by vehicle owners directly with the U.S. Department of Transportation.

Common Causes of P0420 on HONDA ACCORD

50%
25%
25%

Percentages based on NHTSA complaint component analysis for this vehicle.

Complaint Trend by Year

2007
1
2008
1
2010
1
2013
1

What To Do Next

  1. 1
    Check for recalls on YOUR VIN

    Go to nhtsa.gov/recalls and enter your VIN. Free repairs if your vehicle is covered.

  2. 2
    Get a proper diagnosis

    A code alone doesn't tell you the exact failed part. A diagnostic at a shop ($50-$150) pinpoints the root cause before you spend money on parts.

  3. 3
    Compare repair quotes

    Get 2-3 quotes. Dealer vs independent shop prices often differ 30-50% for the same repair.

P0420 on Other Vehicles

Data sourced from the National Highway Traffic Safety Administration (U.S. Department of Transportation) and the SAE J2012 OBD-II standard. Code definitions follow the SAE J2012 / ISO 15031-6 standard. Owner reports are filed directly with NHTSA by vehicle owners. This information is provided for educational purposes only and should not replace professional automotive diagnosis. Always consult a qualified mechanic for vehicle repair decisions.

Last updated: March 2026