🔧 FixIt
🟡

P0420 on HYUNDAI VELOSTER

Severity
Medium
NHTSA Reports
4
Most Affected
2012, 2013, 2015

What P0420 Means on Your HYUNDAI VELOSTER

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

"My car has code of p0420 catalyst system efficiency below threshold. the mechanic i have had look into the cause has suggested replacing the exhaust manifold catalytic converter assembly due to catalytic converter failure. it's a 2012 hyundai veloster 1."

— 2012 HYUNDAI VELOSTER owner • ENGINE • Filed 04/09/2019

"The 2013 hyundai veloster i purchased has had an issue where the car emits a sulfur like smell when accelerating. the safety risk is a faulty engine, and possible exposure to dangerous emissions. upon seeing the check engine light appear, i took it to the hyundai dealer for a diagnostic."

— 2013 HYUNDAI VELOSTER owner • ENGINE,FUEL/PROPULSION SYSTEM • Filed 02/13/2019

"I have a Hyundai Veloster 2015 base (dual-clutch transmission) that has 152,000 miles. I’ve regularly kept up with maintenance. Fully synthetic oil changed every ~5k miles. About a month ago it got a brand new battery and a new alternator. I have some issues related to the transmission."

— 2015 HYUNDAI VELOSTER owner • UNKNOWN OR OTHER • Filed 04/06/2022

"I am the second owner of a 2016 Hyundai Veloster Base, purchased used at approximately 19,976 miles. Since then, the vehicle has experienced multiple major powertrain-related failures. At 49,196 miles, the first catalytic converter failed and was replaced."

— 2016 HYUNDAI VELOSTER owner • POWER TRAIN,ENGINE,FUEL/PROPULSION SYSTEM • Filed 06/04/2025

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 VELOSTER

25%
25%
25%
25%

Percentages based on NHTSA complaint component analysis for this vehicle.

Complaint Trend by Year

2012
1
2013
1
2015
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