2021 Hyundai Sonata fuel/propulsion system problems
18 owner complaints filed with NHTSA name the fuel/propulsion system on the 2021 Hyundai Sonata — 14% of all complaints for this model year.
What owners report
“Engine revving at a complete stop. Surging engine while braking. I was forced to put into neutral when stopping. I had check engine prior that read P049D85. It went away. The Hyundai dealer said to be the EGR valve. Nick Hayes at D'Arcy Hyundai and Hyundai Motor America (HMA) agreeing to a 75%…”
filed Jul 27, 2026
“At approximately 130,000 miles, vehicle developed and internal coolant leak caused by a failed Exhaust Heat Recovery System (EHRS) in the center muffler assembly, matching TSB 23-EM-009H - a known manufacturing defect documented by Hyundai. Coolant has been slowly leaking internally into the…”
filed Jun 24, 2026
Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.
Related service bulletins
Some vehicles equipped with a 2.5L GDI Theta III engine (non-Turbo) may exhibit one or more misfire DTCs due to the GDI fuel injectors leaking internally. This may be caused by internal filter breakage in the injector…
26-FL-001H TSB · Service Bulletin/Repair Instructions · issued Jan 7, 2026
Fuel/propulsion System problems in other Sonata years
| Year | Reports | Share |
|---|---|---|
| 2024 Sonata | 1 | 2% |
| 2023 Sonata | 36 | 43% |
| 2022 Sonata | 22 | 24% |
| 2020 Sonata | 45 | 26% |
| 2019 Sonata | 11 | 7% |
| 2018 Sonata | 30 | 8% |
| 2017 Sonata | 33 | 4% |
| 2016 Sonata | 32 | 4% |
| 2015 Sonata | 72 | 6% |
| 2014 Sonata | 49 | 7% |
| 2013 Sonata | 133 | 7% |
| 2012 Sonata | 99 | 6% |
Other reported problem areas on the 2021 Hyundai Sonata
Counts are unique NHTSA complaints naming this component group. Complaints are unverified owner reports; mileage is computed only from complaints that included a usable odometer reading.