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P0303 on HYUNDAI SONATA

Severity
Medium
NHTSA Reports
3
Most Affected
2016, 2015

What P0303 Means on Your HYUNDAI SONATA

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

"Our 2015 Sonata has experiencing Engine failure several times due to excessive and irregular oil consumption."

— 2015 HYUNDAI SONATA owner • POWER TRAIN,UNKNOWN OR OTHER,ENGINE • Filed 01/22/2025

"Vehicle has been repaired due to broken valve. Vehicle was unsafe to drive. Valve burnt at 70 mph. Car threw misfire code P0303 and started shaking. This issue could have caused an accident. Valves were replaced at Young Hyundai in Ogden Utah."

— 2016 HYUNDAI SONATA owner • ENGINE • Filed 11/20/2024

"I changed out every cylinder, axel, within 6 months and now on March 22, 2023, they said I needed a new engine. P0300, P0303 MISFIRE. They said the car misfired. I thought that's why they changed all the cylinders. WHY DID THIS HAPPEN? My car has been parked in the garage."

— 2016 HYUNDAI SONATA owner • ENGINE • Filed 03/09/2023

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

Common Causes of P0303 on HYUNDAI SONATA

66.7%
33.3%

Percentages based on NHTSA complaint component analysis for this vehicle.

Complaint Trend by Year

2015
1
2016
2

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.

P0303 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