Which parts fail
Components named in complaints (fuel pump, injectors, fuel tank, hybrid and EV propulsion).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2021 Hyundai Sonata owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2021 Hyundai Sonata. The contact stated that while driving at an undisclosed speed, the fuel gauge indicated that the tank was half full. The contact stated that the gauge erroneously indicated that the tank was empty, and the check engine warning light was illuminated. The vehicle was driven to the gas station, and while attempting to refuel the vehicle, the fuel did not go into the tank. The vehicle was towed to the residence. The vehicle was later towed to the dealer, where it was diagnosed with a failed fuel system and a failed fuel tank. The contact was informed that the fuel system and fuel tank needed to be replaced. The vehicle was not repaired. The contact was informed that the failure was associated with the unrepaired recall. The contact was informed that the vehicle was a fire risk. …
The contact owns a 2021 Hyundai Sonata. The contact stated that while driving at an undisclosed speed, the accelerator pedal was depressed; however, the vehicle failed to accelerate as intended. The vehicle was driven to the shoulder of the road. The contact stated that the fuel level indicated empty, and the low fuel warning light was illuminated. The passenger seated in the rear seat noticed that the rear seat was out of place and that the seat was very hot. The vehicle was refueled prior to the failure. The contact and the other occupants in the vehicle exited the vehicle. The vehicle was towed to the residence. The dealer was made aware of the failure. The contact was informed that the failure was like the failure listed in NHTSA Campaign Number: 25V796000 (Fuel System, Gasoline). The contact was unaware of the open recall because a recall notification was not received. …
The contact owns a 2021 Hyundai Sonata. The contact received notification of NHTSA Campaign: 25V796000 (Fuel System, Gasoline); however, parts were on back order. The contact stated that while driving at an undisclosed speed, the vehicle jerked with an abnormal gasoline odor inside the vehicle. An unknown warning light was temporarily illuminated. Upon further inspection, the contact became aware that the fuel level had dropped. The vehicle was taken to a local dealer where it was diagnosed with an expanded fuel tank. The contact stated that the O2 sensor, spark plugs, and ignition coils were replaced by a local independent mechanic; however, the failures persisted. The contact had headaches while driving the vehicle. Medical attention was not needed. The manufacturer was made aware of the failure. The failure mileage was approximately 100,000.
The contact owns a 2021 Hyundai Sonata. While driving at various speeds, the vehicle unexpectedly shut off without warning. There was an abnormal popping sound coming from the vehicle with an abnormally strong fuel odor inside the vehicle. The contact stated that the vehicle was consuming an excessive amount of fuel. The contact received notification of NHTSA Campaign Number: 25V796000 (Fuel System, Gasoline); however, the part to do the recall repair was not yet available. The local dealer and the manufacturer were not notified of the failure. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. The failure mileage was approximately 70,000.
The contact owns a 2021 Hyundai Sonata. The contact received notification of NHTSA Campaign Number: 25V796000 (Fuel System, Gasoline); however, the part to do the recall repair was not yet available. The contact stated that while driving at an undisclosed speed, the vehicle independently accelerated and decelerated while the accelerator pedal was depressed. The check engine warning light was illuminated. The vehicle was towed to a local dealer where it was diagnosed with an expanded frame due to an expanded fuel tank. The vehicle was deemed too expensive to repair per the local dealer and was towed for a buy-back. The manufacturer was made aware of the failure, but no assistance was provided. The failure mileage was approximately 55,000.
The contact owns a 2021 Hyundai Sonata. The contact stated that while driving at an undisclosed speed, the accelerator pedal was depressed; however, the vehicle failed to accelerate as intended. In addition, the contact stated that the vehicle was shaking abnormally. The vehicle was taken to the dealer; however, the contact was informed that the part was not available to repair the vehicle. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. The contact received notification of NHTSA Campaign Number: 25V796000 (Fuel System, Gasoline); however, the part was not available for the recall repair. The manufacturer was made aware of the failure, and a case was filed. The failure mileage was approximately 92,000.
The contact owns a 2021 Hyundai Sonata. The contact stated while driving at various speeds, he smelled an abnormally strong fuel odor inside the vehicle. There were no warning lights illuminated. The vehicle was taken to the dealer who informed the contact that they could duplicate the failure. The vehicle was then taken to a second dealer, Wayne Hyundai Parts and Service (1244 NJ-23, Wayne, NJ 07470) who could not duplicate the failure. The failure persisted. The contact stated that after driving the vehicle, his entire body had a strong fuel odor. The manufacturer was notified of the failure and referred the contact to another dealer. The vehicle was not diagnosed or repaired. The failure mileage was approximately 21,000.
The contact owns a 2021 Hyundai Sonata. The contact received notification of NHTSA Campaign Number: 25V796000 (FUEL SYSTEM, GASOLINE); however, the part to do the recall repair was unavailable. The local dealer was contacted, and it was confirmed that the part was not yet available. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. The vehicle was taken to the local dealer, and the contact was informed that the fuel tank was swollen and needed to be replaced. The vehicle was not yet repaired. The failure mileage was 80,484.
The contact owns a 2021 Hyundai Sonata. The contact stated while driving at an undisclosed speed, the engine shuddered and the engine stalled. In addition, the engine seized. No warning lights were illuminated. The contact stated that the vehicle was seized in the middle of the road. The contact stated that while attempting to start the vehicle, the vehicle started. The failure reoccurred. The vehicle was towed to the residence. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. The manufacturer was made aware of the failure. The failure mileage was approximately 140,000.
The contact owns a 2021 Hyundai Sonata. The contact stated while pulling out of a parking lot, the vehicle failed to accelerate as intended and started shaking abnormally. The check engine warning light was illuminated. The vehicle was taken to the residence. The vehicle was towed to an independent mechanic where it was diagnosed that the fuel injector needed to be replaced. The vehicle was towed to a dealer where it was diagnosed that all four fuel injectors needed to be replaced. The vehicle was repaired. The manufacturer was not notified of the failure. The failure mileage was 47,000.
Related recalls
Fuel system, gasoline
Hyundai Motor America (Hyundai) is recalling certain 2020-2023 Sonata vehicles. A damaged check valve can allow air to enter the fuel tank, causing it to expand and contact hot exhaust components, melting the tank.
Remedy: Dealers will inspect and replace the check valve. The fuel tank assembly will be inspected for damage and replaced if necessary. Additionally, dealers will inspect and update the engine control unit software.
Fuel system, gasoline › Delivery › Hoses, lines/piping, and fittings
Hyundai Motor America (Hyundai) is recalling certain 2021-2022 Santa Fe and Sonata vehicles equipped with 2.5L turbocharged engines. Fuel may leak at the pipe connection between the high-pressure fuel pump and fuel rail.
Remedy: Dealers will inspect and tighten, or replace the fuel pipe as necessary, free of charge. Owner notification letters were mailed on September 3, 2021. Owners may contact Hyundai customer service at 1-855-371-9460.
Fuel System complaints in other Sonata years
Frequently asked questions
How common are fuel system problems on the 2021 Hyundai Sonata?
NHTSA has 34 complaints about the fuel & propulsion system of the 2021 Hyundai Sonata, 25% of the model year's 134 complaints. The component named most often is fuel injection system › injectors (1 mentions).
Is there a recall for 2021 Hyundai Sonata fuel system problems?
Yes — NHTSA recall 25V-796 (fuel system, gasoline, Nov 17, 2025); NHTSA recall 21V-524 (hoses, lines/piping, and fittings, Jul 9, 2021). Recall repairs are free at authorized dealers.
At what mileage do 2021 Hyundai Sonata fuel system problems start?
Half of the complaints with a recorded mileage happened before about 80,000 miles, and 10% before 25,000 miles.
Is it dangerous?
Owners linked 1 crash, 0 fires and 6 injuries to fuel & propulsion system problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.