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P0420 on HYUNDAI ACCENT

Severity
Medium
NHTSA Reports
2
Most Affected
2012, 2016

What P0420 Means on Your HYUNDAI ACCENT

Real HYUNDAI ACCENT Owner Reports (Source: NHTSA Complaints Database)

"The engine light is blinking on the dashboard and making too much sound from the engine, took the car to mechanic he said problem with o2 sensors and catalyst system effieciency (p0420) code"

— 2012 HYUNDAI ACCENT owner • SUSPENSION,ENGINE • Filed 10/24/2019

"2016 Hyundai Accent only has approximately 132,000 miles and needs a new engine. Three different mechanic shops (one being a Hyundai dealership) looked at the vehicle and determined that it needed a new engine due to engine knock in lower end of engine."

— 2016 HYUNDAI ACCENT owner • ENGINE • Filed 01/12/2022

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 HYUNDAI ACCENT

50%
50%

Percentages based on NHTSA complaint component analysis for this vehicle.

Complaint Trend by Year

2012
1
2016
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