Been having an issue with a check engine light and a popping noise in the from the front of the vehicle for about two years. Took it to the dealership more than 3 times over that span and every time they discovered it was caused by something different..during the July of 2024 while driving on the interstate a loud pop noise was made from the back and my children complain about the seat lifting-??shortly after I went to get gas and a full tank was more gallons than usual 14 increased to 17g-??. I once again took it to the dealer for the issue of the gas tank expansion and pop but found nothing. No more than a week later my car would hesitate to accelerate and progressively got worse. On 12/27/24 I took it to the dealer and they discovered my gas tank was expanded and was unsafe to drive leaving me without a vehicle.as of 1/04/2025 I still have no solution.

- Cheeapeake , VA, USA

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.

- Lakeland, FL, USA

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)

- Jamestown, SC, USA

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)

- Pensacola, FL, USA

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.

- Bowie, MD, USA

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

- Wailuku, HI, USA

I had the check engine light come on about 4 times in my 2020 Hyundai Sonata 1.6L this year in 2024. I took the car to a technician to get looked at each time it came on. The codes and bulletins kept pointing to fuel system issues. Each time, every service tech said it was a small issue and claimed to fix the issues. The final time a tech seen it lifted the rear seat and found out that the gas tank expanded and the back seat buckled up. The backseat metal frame is bent and messed up. I was flagged down by several drivers "that noticed gasoline leaking from my driverside rear. My child and I were in dang" er and had to pull on the side of a major highway and stay several hours until someone picked us up. The problem has been confirmed by the hyuandi service center. They said another vehicle experienced this same issue. I was in fear for my life and my child's life because it could have caught fire and/or exploded.

- Baltimore, MD, USA

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.

- Oklahoma City, OK, USA

(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.

- Clearwater, FL, USA

Gas tank is swelling causing the rear seats to pop

- Orlando, FL, USA

On July 15th I was driving away from work and my car suddenly stopped accelerating. I was able to get it towed to a body shop I previously had it repaired at. They said the battery system was blowing a fuse when it would become undrivable. They took it to the local Hyundai dealership where they applied a new software update related to the battery management system. This did not solve the issue, it continues to stop while in traffic and the dealership refuses to do anything to figure out the cause.

- Marietta, GA, USA

Took a trip to Nashville so I left Memphis Saturday morning hole on the road heading to Nashville I was at least 30 minutes fork the city my car began to jerk very bad suddenly my file light came on so I stopped at a gas station the file light came on telling me I needed gas the had was on the E but my mileage to e said 117miles. So I was like ok that-??s weird after I put gas in my car I got back on the road my gas hand went from full to half way and I was not even on the road for 40 minutes so as we get closer to Nashville my car starts jerking very bad I hear a noise that sounded like a bag or a piece of paper being crumbled up I turn around to find my rear seat up in the air I knew it was not normal at all looks like it was a lot of pressure for the frame of a car to stand up like that I definitely knew something was wrong when that happened I instantly started to smell gas very loud smell of gas I then start to do my research and I see Kia-??s and Hyundais are dealing with gas tank expansions so at this point I am scared for my life I-??m in my car and I-??m dealing with a issue like this. I instantly call my dealership and schedule to have my car towed to the dealership out in Nashville. They called me that Monday confirming the gas take had expanded and caused a significant amount of floor damage to my vehicle I am currently waiting trying to see what is Hyundai going to do about this issue that is my only transportation and having to deal with this then find another way back home has been very stressful and just to know that I could have lost my life in that car is even more traumatic

- Memphis, TN, USA

Fuel tank has expanded to the point that my vehicle is deemed not safe to drive. As pressure in the tank is unable to be stabilized. Only had the car for about 70 days since the date of purchase. Repairs are about $3900. In short as told by the dealership service department, my car could blow up at any time. This is not safe, at all.

- Simpsonville, SC, USA

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.

- Enterprise , AL, USA

I was on my way back home from Alexandria LA on [XXX] when I heard like the sound of an blow out tire but wasn-??t happen to look in back of car and seen back seat was blown off the area of the car and proceeded to see that the gas tank was expanded like you would see a balloon and the me car started running funny and. Then a service code comes across the screen of the radio po45100, so I pull over and look beneath the car and see that the gas tank is so expanded it-??s now pressing against the exhaust pipe. So I turned car off and here we are now I-??m without a car due to this. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

- Anacoco, LA, USA

A week before my gas tank expanding I heard a loud popping noise. When driving from NC to DC, my gas tank refused to take gas and my car immediately went to empty. I was stranding on the highway and has my 2020 Hyundai towed to the Hyundai dealership in Chesterfield, VA. They told me that my gas tank expanded and my back seats had popped out of place.

- Laurel0, MD, USA

It looks like the fuel tank has expanded. My back seats are now lifted & will not push down.

- Dallas , TX, USA

Driving 55mph on highway car slows down and make a pop nose and back seat comes up and I start to smell gas

- Memphis, TN, USA

I have a 2020 Hyundai Sonata SEL Plus. For the past month I been dealing with my CEL regarding Fuel Tank Pressure sensor and I end up replacing one from hyundai itself. After doing that I notice my fuel tank has expanded and I-??m currently dealing with Hyundai & the dealership to see if they can make a recall regarding this issue or just fix it period since it-??s a big safety concern. This been happening since mid April. My back seat lifts up from time to time and my fuel pump cover is bent. Below I-??ll add some pictures so you guys can see how my tank straps are actually bent which is very uncommon for it to happen. I recently took it to the dealer last week after reaching out to hyundai corporate and they took pictures and send it for prior approval to see if hyundai is willing to replace this. I can-??t fill up my gas tank, I constantly have to out between $15-$25 the most due to fuel mileage issue since the tank has expanded I get fuel mileage inconsistency

- Ocala, FL, USA

An independent service center advise us that the gas tank had expanded which could have put my family at risk if exploding or catched on fired. This happend on June 15th 2024 while driving, a sudden explosion coming from the back of the car was heard. Little after the explosion like sound we perceived as if air was coming through the back as if we had a window rolled down. When pulled to check, i notice that the back seat was popped up. No warning on the car was giving prior to the incident. Will take car to Hyundai dealership to have it inspect by them and have a solution.

- Somerton, AZ, USA