2020 Hyundai Sonata Fuel System Problems

The contact owns a 2020 Hyundai Sonata. The contact stated that while attempting to start the vehicle, the vehicle failed to start. The battery and the key warning lights were illuminated. The contact stated that after several attempts, the vehicle started. The vehicle was driven to the end of the driveway and turned off. The contact was afraid of driving the vehicle due to the failure. The independent mechanic was made aware of the failure. The contact was informed of an open recall. The dealer was made aware of the failure and confirmed the open recall information. In addition, the contact was advised that the failure might be because of the unrepaired recall. The contact was advised to bring the vehicle in for diagnostic testing. 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, parts for the recall repair were not yet available. The failure mileage was approximately 42,947.

The contact owns a 2020 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 local dealer was contacted. 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 contact had not experienced a failure.

Vehicle subject to NHTSA Recall 25V796000 (fuel system defect). In July 2025, while driving, a loud explosive sound came from the rear of the vehicle followed by raw gasoline fumes entering the cabin. Vehicle was towed to a Hyundai dealership and held approximately 120 days before being returned as repaired. In December 2025, the exact same defect recurred. A third-party diagnostic scan (performed before drop-off) confirmed DTC Code P14EE — Fuel Tank Check Valve / Evaporative Purge System failure — directly related to the recall. The vehicle was held an additional 110+ days while the dealer awaited a new remedy from the manufacturer. Total days out of service: 230+. The recall repair has now failed twice. The safety defect was never successfully corrected after a reasonable number of attempts. The vehicle is currently being withheld by the dealership pending an unrelated disputed repair charge.

It was about 100 degrees outside yesterday, and while trying to pass a car, I look in my rearview mirror and notice there is fuel shooting out from my fill hose under my gas flap. I lost over 3 gallons of fuel on the road. This happened my whole 60 mile trip. This has happened to me before, but the temperature was around 76 degrees and it does not happen in cold weather. I have a feeling my fuel tank is expanding because when I took out my back seat where my fuel tank is located, the body of the car is all buckled up to the point where I can't get my backseat to latch down anymore. My car is available anytime for inspection upon request. I have not taken it to a dealer to get it looked at, there has not been a police report filed. And there were no warning lights or indicators other than a popping sound coming from my backseat area before the problem occurred. There are no warning lights or indicators after the problem either. I feel like I'm driving a bomb because my fuel tank could blow up at any time. This problem can be reproduced anytime by filling the tank and driving it in 90 degree weather.

Something went wrong in the fuel tank that caused it to become so pressurized that the tank expanded up and out so far that it pushed the exhaust pipe down and my back seat of out place. The only issue I had was the car was accelerating slower than usual but it wasn’t even enough of a difference for someone who didn’t drive it every day to be able to tell. It did this for two days then the check engine light came on and it just read “powertrain”. Began slow acceleration on 06.08.2025. Check engine light came on the night of 06.09.2025. I took it to the dealership 06.10.2025. I immediately took it into the dealership and they told me the car could have exploded. There was a previous recall for the fuel pump that I had replaced at the dealership. After seeing my car, they said their techs and the techs at HMA have never seen one this bad and that maybe after replacing the recall part the system update failed in my vehicle and the issue was never actually resolved.

I received a notice in the mail my car needed a software update. I went to the dealership to have the update performed. They informed me there was a service campaign for an expanding fuel tank due to pressure. They were unable to return my car to me at that time stating they were awaiting direction from Hyundai Motor of America for the fix. The fuel tank expanded so much it bent the body of of the car underneath the backseat. It also broke the support straps. The dealership stated it was a known issue with a vent valve. Causing the fuel tank to swell so much it damaged the body. They have had my vehicle for 9 weeks with no direction as to what to next.

I experienced an issue where the gas tank in my 2020 Sonata began to swell and emit loud popping noises while the vehicle was parked. I took it to the dealership, and Hyundai corporate eventually acknowledged the issue and agreed to buy out my loan. However, no official recall has been issued for this model year. This problem has had a major impact on my life. I lost my job due to not having transportation for over two months, and the stress of not knowing whether my vehicle was safe made it even worse. I had to upgrade my insurance for a loaner I never received, take financial hits, and go into deeper credit trouble—all while also recovering from a serious injury from a previous car accident. I now have to start over with a new loan while my credit is already damaged. I’m submitting this report not just for myself, but to ensure that other 2020 Sonata owners are protected and made aware of this issue. I believe this is a serious defect that warrants official investigation.

Fuel system expanded back seat

I took my vehicle in for an oil change and was advised that my car failed a recall. The PCV valve failed. After the dealership, explain this problem to me I no longer feel safe driving this vehicle. Imagine being told that the fuel tank can expand and pop up the backseat of your vehicle at any given moment or even cause the car to blow up and no warning lights coming on to alert you that this part had a defect.

The contact owns a 2020 Hyundai Sonata. The contact stated while the contact was refueling the vehicle, the fuel was coming back out of the fuel tank onto the ground surface. The contact stated that the failure had occurred while traveling out of town. In addition, the contact stated that the failure had occurred several times and the check engine warning light illuminated. The vehicle was taken to an independent mechanic where it was diagnosed a failed fuel tank sensor. The contact was informed that the fuel tank sensor light. The contact stated that when the independent mechanic pulled out the rear seat to perform the repair, the mechanic noticed that the metal sheet under the rear seat was fractured due to the pressure of the fuel tank. The vehicle was not repaired. The contact was advised to take the vehicle to the dealer. The vehicle was taken to the dealer, however the dealer declined the repair. The contact was advised not to drive the vehicle and informed that the vehicle was a ticking bomb. In addition, the contact was advised to take the vehicle to a collision shop, prior to the repair being performed. The vehicle was not repaired or diagnosed by an independent mechanic or the dealer. The contact's insurance declined the repair stating that the failure was due to a manufacturer defect. The manufacturer was made aware of the failure and a case was filed. In addition, the contact was informed that the repair was not covered under warranty because the contact was the second owner of the vehicle. In addition, the contact's vehicle mileage was above the 60,000 mileage warranty coverage. The failure mileage was approximately 99,230.

I was driving back from Atlanta, GA to Pensacola, FL when we noticed our fuel level dropping significantly. We stopped in West Point, GA to see what was going on. We turned the car off and back on after 3 minutes and car made a weird vibration. Then the fuel level was rising back to normal but my wife was in the backseat with our [XXX] and she noticed the seat was rising and creating a lot of heat. We pulled over again and noticed it wasn't going down. Luckily there was a mechanic at this gas station and he informed us that the fuel tank expanded and to NOT drive the vehicle. We we're driving alongside my parents so we got in their car and drove back to Pensacola to get a truck and tow attachment cause a tow truck would've costed us $2,500 to tow back to Pensacola. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The component that failed is the fuel tank system. While driving, the fuel tank expanded, causing significant damage to the rear section of the vehicle. This issue resulted in the rear seat rising up, and the bottom rear seat cushion detaching from its securing clamps. The check engine light came on, and gas started leaking from the fuel cap. The fuel tank has moved upward by about 3 to 5 inches, no longer resting on the factory fuel tank straps. The sheet metal underneath the rear seat was crumpled, and the fuel pump access cover bent. The vehicle is currently at College Park Hyundai and is available for inspection upon request. My safety and the safety of my children were significantly compromised. The loud popping noise startled us, and the fact that the rear seat lifted and detached posed a serious risk to the passengers in the back seat. Additionally, the gas leak created a fire and explosion hazard, putting all occupants of the vehicle and other drivers on the road at serious risk. This incident potentially violates the Fuel System Integrity (49 CFR 571.301) regulation, which ensures that a vehicle's fuel system is designed to prevent leaks and fire hazards. Moreover, the unexpected movement and detachment of the rear seat could be a breach of Occupant Protection (49 CFR 571.207 and 571.208), which govern the safety of seating systems and occupant crash protection. The issue has been confirmed by the service center at College Park Hyundai, where the vehicle is currently being inspected and evaluated. The vehicle is being inspected by the manufacturer’s authorized service center at College Park Hyundai. It has not yet been inspected by police or insurance representatives at this time. The check engine light came on immediately after the loud popping noise and the detachment of the rear seat cushion. Additionally, the gas gauge suddenly dropped to empty after the incident, even though the tank was not empty prior to the malfunction.

(August 29th) My girlfriend and I were driving in my 2020 Sonata, when the check engine light turned on and my gas gauge dropped from being full to then only half way. About an hour later, driving back home we heard a loud pop as if something exploded. Next day, I took my car to the Autonation Hyundai dealership and after taking a look at my car they quoted me about $6,000 to get my fuel tank and charcoal canister replaced. Our safety was put at risk due to the fact that had the damage been any worse, it could have caused the car to possibly explode or give out while driving on the highway, and in turn would put many more lives at risk.

Gas tank replaced three times and failed each installation (excess pressure)leaked gas with riders in car. I was a LYFT driver .YES car can be seen at MAUI HYUNDAI SERVICE DEPT 260 HANA Highway. Kahului, HI. 96732 Car needs another gas tank and Manager at Service Dept tells me there is only one gas tank available, the type we installed. FARMERS INSURANCE HAS SEEN PHOTOS OF THE BAD GAS TANK. Service department was not aware of this gas tank issue...told me you must have run over some debris (not true) HYUNDAI has received my complaint but not replied yet.Engine warning light came on went off came on Took car to dealer for service

The contact owns a 2020 Hyundai Sonata. The contact stated while driving at an undisclosed speed, there was an abnormal gasoline odor inside the vehicle. The contact then heard a loud pop and pulled over to the shoulder of the roadway. After a visual inspection, the contact observed gasoline leaking from the fuel tank filler neck, even though the access door and gas cap were both securely closed. The check engine warning light was illuminated. The vehicle was taken to an independent mechanic, who diagnosed a failure with the canister purge valve, causing the fuel tank to swell, resulting in damages to the fuel pump. The vehicle was not repaired. The manufacturer was notified of the failure, and a case was opened. The failure mileage was 47,000.

There is an issue with the 2020+ Hyuandai sonatas and Kia K5 models. The valves in my gas tank had failed. Causing pressure and gas vapors to be trapped inside the tank. The pressure in my tank has swollen my gas tank to the point where it’s bent the metal frame underneath my backseat, lifting my backseat off its base. My car is a literal tricking time bomb because the tank will eventually burst. There’s also a strong smell of gas coming from underneath the backseat. There’s been a new story on this issue already. Kia has acknowledged the issue and did recalls. Hyundai has not. Many owners of the Sonata are having this same exact issue according to Reddit posts. I took my vehicle to the dealer, got it diagnosed, was quoted $2900+. I was told it was an extreme safety hazard due to the pressure in the tank and the gas leak. The tank has swollen so much that it’s pressing against the exhaust. I’m out of warranty and they expect me to pay out of pocket. I have no where near $3000. I use my car for work and have no choice but to drive it. Please help.

What component or system failed or malfunctioned, and is it available for inspection upon request? The Fuel Tank expanded, was leaking gas from the gas tank opening. The expansion of the tank caused the metal plates/panel under the back seat to popup, where my child sits. Which caused a gap in the door. ir seepage from the back seat passenger door to where the fuel was leaking out the gas tank and also the fuel gauge on the dash was fluctuating. People on the highway was flagging me to let me know fuel was leaking. The fire department had to come and clear it. How was your safety or the safety of others put at risk? My child and I could have been seriously injured or killed. As well as people on the highway. It could have exploded. You can smell the gas in the car. The gas was coming out the gas tank on the side. Has the problem been reproduced or confirmed by a dealer or independent service center? Yes, it was confirmed by Hyundai of North Charleston 8485 Rivers Avenue, North Charleston SC, 29406 and it was also checked by the insurance adjustor. Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? It was inspected by the Insurance representatives State Farm Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? No I took it into the dealer and they said it was fixed and it did not fix the gas coming out the tank. And the same issue happened again on [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Gas tank is swelling causing the rear seats to pop up

Riding down the road June 30, 2024 and heard a loud boom coming from the back of my car. I pulled to the side of the road and walked around but saw no damage to outside of car. When I was approximately 30 miles from home my gas started dropping tremendously. Once arriving at home it was a rumble coming from rear of car after inspecting outside car and seeing no damage again, I looked in my back seat and the rear seat was lifted. If my kids or any other occupants would have been back there it could have possibly caused injuries. Upon my mechanic looking my car over they told me it was something to do with my fuel tank. My appointment is July 16, 2024 Hyundai of Dothan in Dothan al for farther diagnosis. My safety was in danger as explosion from the fuel tank could have cause serious damage and/or injury to car and self. Check engine light came on once the fuel consumption started dropping tremendously.

The contact owns a 2020 Hyundai Sonata. The contact stated that while driving at an undisclosed speed, there was an abnormal gasoline odor inside the vehicle, after which the vehicle lost motive power. The contact pulled over to the shoulder of the roadway, moved the rear seat, and observed that the fuel pump was protruding upwards. The check engine warning light was illuminated. The vehicle was towed to the dealer, who diagnosed a failure with the purge valve, resulting in damages to the fuel pump and fuel tank. The vehicle was repaired, but the failure reoccurred. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline for assistance. The failure mileage was approximately 47,000.