2021 Hyundai Sonata Fuel system Problems

Gas tank expansion and pcv melted. Car smells like gas when I was driving earlier, and my garage was flooded with the fumes of gasoline.

NHTSA ID

11755570

Incident

Aug 7, 2026

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. In addition, the contact was informed that there was a hole in the fuel tank that caused the fuel to leak out of the fuel tank. The contact was informed that the parts were ordered to repair the vehicle. The contact received notification of NHTSA Campaign Number: 25V796000 (Fuel System, Gasoline). The manufacturer was not made aware of the failure. The failure mileage was approximately 50,200.

NHTSA ID

11754791

Incident

Jul 28, 2026

Mileage

50,200 mi

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% goodwill split of cost to repair.

NHTSA ID

11753130

Incident

Jul 25, 2026

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.

NHTSA ID

11753027

Incident

Jul 27, 2026

Mileage

80,484 mi

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 exhaust system. The authorized Hyundai dealership initially failed to diagnose the internal leak and told me there was no leak and wanted to send me home. After pushing back, the internal leak was confirmed. If not caught, this defect could result in engine overheating or complete engine failure without warning. Hyundai Motor America has denied goodwill coverage despite this being a documented manufacturing defect.

NHTSA ID

11746137

Incident

Jun 22, 2026

I took my car to dealer to repair recall. Dealer told me if it failed they would keep car and report stolen if I tried to take it. They failed it. I didn't trust them based on their report it stolen statement. I had the police get my car back. I took it to another dealer where it passed recall easily. I believe they wanted my car for a customer, and tried to get away with this ruse.

NHTSA ID

11739443

Incident

Mar 24, 2026

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.

NHTSA ID

11738864

Incident

May 18, 2026

Mileage

140,000 mi

I was notified of a recall on my from vehicle by Hyundai via email some time in March of 2026. The message said mentioned my vehicle may have a defective/worn purge control check valve that would cause the fuel tank to deform. Potentially leading to a release of fuel over time, which then could ignite. NHTSA Recall #25V796000 My car showed now signs of problems, but I brought it into a Hyundai dealership on March 13th where they confirmed my vehicle had the issue. They said the situation required I not drive my vehicle and gave me a rental in the meantime. I assumed it would be a simple swap of the fuel tank and everything would be fine. I was offered a buyback from my Hyundai claims manager over the situation, but I figured since its a simple fix, I'd keep my car and have it fixed. Two weeks went by with no update from the dealership, so I walked in for answers. Turns out, the subframe of my car has been damaged by the expanding fuel tank and they are still waiting for updates from Hyundai on how to proceed as they themselves don't know how to fix my vehicle. My Hyundai claims manager did not mention this when we talked over the phone and he offered a buyback. None of their recall notices mention structural damage anywhere or even as a possibility. I asked the dealership again on April 1, 2026, and they are still waiting on guidance on how to proceed. Neither does my Hyundai claims manager handling this situation on their end.

NHTSA ID

11729119

Incident

Mar 13, 2026

The internal core of the Exhaust Heat Recovery System (EHRS), part of the center muffler/front pipe assembly (#28600-L5210), suffered a catastrophic failure. This allowed approximately 9 gallons of engine coolant to leak directly into the hot exhaust stream. Safety Risk: This failure creates a severe visibility hazard. During acceleration from stop lights and stop signs, the vehicle emits massive, thick clouds of white glycol smoke. The smoke is so dense that it completely obscures the driver's view of trailing vehicles and prevents following drivers from seeing the roadway or my vehicle's brake lights, creating a high risk of rear-end collisions. Additionally, the rapid loss of coolant caused the engine to overheat and lose power while in motion, nearly causing a stall in active traffic. Confirmation: The failure was confirmed by the service department at Washington Hyundai (Invoice #174281). This is the second failure of this specific component (previously failed in Jan 2025). The manufacturer issued TSB 23-EM-009H for this defect, acknowledging it affects 2020-2023 Sonata Hybrids, but no safety recall has been issued. Symptoms: The issue was preceded by a "sweet" burning smell and a sudden "Engine Overheating" warning on the dashboard. The failed component has been replaced by the dealer, but the manufacturer refused to replace the coolant-poisoned Oxygen (O2) sensors, leaving the vehicle in a technically compromised state. The failed unit is likely held by the dealer for warranty parts return.

NHTSA ID

11727380

Incident

Feb 19, 2026

The contact owns a 2021 Hyundai Sonata. The contact received notification of NHTSA Campaign Number: 25V796000 (Fuel System, Gasoline); and the vehicle was taken to the dealer for the recall repair; however, the dealer informed the contact that the vehicle was unrepairable, and there was no further information provided. The manufacturer was made aware of the issue, and a case was filed. The manufacturer informed the contact that the field engineers had reviewed the vehicle and advised that a buyback was the best option. Additionally, the manufacturer offered an 8 percent discount on the purchase of a new vehicle. The contact declined the offer because the vehicle had not experienced a failure, and the vehicle would be paid off after two additional payments.

NHTSA ID

11725496

Incident

Mar 19, 2026

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 vehicle was not diagnosed or repaired by an independent mechanic or dealer. The manufacturer was not made aware of the failure. The failure mileage was approximately 130,000.

NHTSA ID

11721548

Incident

Mar 1, 2026

Mileage

130,000 mi

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 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.

NHTSA ID

11720224

Incident

Nov 17, 2025

On i believe 1/14/26, my check engine light came on. Scheduled appt.for 1/16/26 for diagnostic. Several things were wrong. I decided to come back due to not having the money at the time. Over the wked, I remembered a recall notice i received around November that I asked about in November during my oil change & was told the parts aren't in & they'd give me a call. Upon viewing the recall it seemed some things I was told on 1/16/26 could be a result of the recall. I called my service person Linda on 1/20/26, she spoke to her supervisor & they informed me some of the issues seem to stem from the recall. Linda gave me the manufacturer recall contact information. I contacted them on 1/20/26. She explained there was indeed a recall, there wasn't a remedy yet, it was safe to drive & if something changes, to call back. On 1/28/26 around 5:30am I left home for work & my car all of a sudden experienced a loss of power. It wouldn't go past 30mph. I returned back home & called out of work. I called the manufacturer recall & informed them. She made an appt. to take my car in the follow day, 1/29/26. I decided to drop it off that same day, 1/28/26. I had someone follow me being i could only go 30mph on a flat road & 10mph on a slight hill. I found out my service person Linda was no longer employeed there. I spoke with another employee. He said they would have to do another diagnostic. I left my car. I called the dealership on 1/29/26 for an update, they had not looked at my car. I called the manufacturer recall, they assigned a case manger to my case. Jay from the NCA, called me on 1/30/26 I believe. We've communicated several times without me receiving a adequate update. He's saying the issue seems to be steamed from the recall, there is now remedy yet, & they are still investigating. I've been without a car since 1/28/26, still making payments, missing work, haven't been offered a loaner & have no idea when or if I will get my car back.

NHTSA ID

11719681

Incident

Jan 28, 2026

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.

NHTSA ID

11716730

Incident

Aug 1, 2024

Mileage

70,000 mi

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.

NHTSA ID

11716213

Incident

Nov 25, 2025

Mileage

92,000 mi

I took my car to the dealer on [XXX] with concerns about the strong gas smell that I have been smelling. The Hyundai dealership kept my car for 3 days and stated they could not smell the gas after driving the vehicle themselves. They did repair a cracked cylinder head however they did tell me that it wouldn't have been the cause of the fuel smell. They stated next time I am out driving, and I notice the smell to "pop" into the dealership to have it checked again. While this is good in theory, it is not something I am just able to do. I am [XXX], one of which is still in a car seat and unable to unbuckle themselves to get out if something terrible like a fire was to arise. This was the 2nd time taking my car in, as it was previously fixed in Feb 2025 due to another recall on the gas tank expanding. I do not feel safe transporting my children in a vehicle that is still reeking of gas and a possible hire hazard with no resolution. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11712843

Incident

Jan 7, 2026

I was driving my 2021 Hyundai Sonata at approximately 3:00 AM when the vehicle suddenly began shaking and vibrating. While stopped at a traffic light, the check engine light illuminated, and the engine was shaking severely. I immediately pulled over and shut off the engine. After waiting approximately one hour, I restarted the vehicle, but it was only able to drive very slowly. The following day, the vehicle was towed to a local repair shop. Diagnostic testing showed a cylinder 3 misfire, along with EVAP system errors and faulty fuel injector issues. This failure occurred without warning and created a potential safety risk while driving. I am concerned this may be related to a defective fuel system.

NHTSA ID

11709821

Incident

Jan 7, 2026

Please see Attachment To Whom It May Concern, I am writing to formally notify you under the Virginia Motor Vehicle Warranty Enforcement Act (Virginia Lemon Law, Va. Code §§ 59.1-207.9 to 59.1-207.16) that my 2021 Hyundai Sonata, has a nonconformity that substantially impairs its use, value, or safety. On June XX, 2025 I delivered my vehicle to Pearson Hyundai for repair due to the fuel pump recall. As of today September XX, 2025 the vehicle has been out of service for more than 89 days, well beyond the 30-day threshold set by Virginia law. Despite this, the manufacturer has failed to complete the required recall repair in a reasonable amount of time. This constitutes a violation of my rights under Virginia’s Lemon Law. Therefore, I am formally demanding relief as provided by law: Repurchase of my vehicle for the full contract price, including taxes, fees, and incidental charges, less a reasonable allowance for use, OR Replacement with a comparable new vehicle acceptable to me. Please respond in writing within 15 days of receipt of this letter. If this matter is not resolved, I will be forced to escalate through the Virginia Attorney General’s Office, the National Highway Traffic Safety Administration (NHTSA), and, if necessary, legal action.

NHTSA ID

11709594

Incident

Jan 1, 2025

I own a 2021 Hyundai Sonata 1.6T, which has an open NHTSA safety recall (25V796000) related to fuel tank pressurization and fire risk. I brought the vehicle to an authorized Hyundai dealership due to a check engine light, reduced performance, and DTC P14EE, which aligns with the recall condition. The dealership refused to treat the concern as recall-related unless I paid a diagnostic fee and later attempted to reclassify the issue as a customer-pay fuel pump repair. During this visit, the dealership replaced a fuel system sensor without my authorization, which I did not approve or consent to. The dealership has not provided documented test results explaining how the recall condition was ruled out and has not documented recall inspection on the repair order. I expressed that I do not feel safe driving the vehicle due to the fuel system recall and drivability issues. The dealership also refused to provide alternate transportation. I am concerned the recall is not being handled in compliance with NHTSA requirements and that unauthorized repairs were performed while attempting to shift a recall-related condition to the customer. I am requesting review of recall handling and dealer compliance.

NHTSA ID

11707864

Incident

Dec 29, 2025

Recall number (25V796000) There is No remedy available. I am Experiencing fuel system issues that may relate. Dealer and corporate refusing meaningful support and expecting me to pay $1,600 to replace fuel assembly. I feel unsafe driving my vehicle at this time.

NHTSA ID

11707812

Incident

Dec 30, 2025

I bought this car in June 2013 for its safety and its Amazing warranty and all the features that it has Hyundai manufacture had an obligation as a consumer service and failed to send notification of any recalled to us in regards to a recall High pressure, fuel pump, and fuel rail Fuel system engine, gas tank This is a product of liability and negligence on time but they failed to take responsibility and comply with federal laws. I was driving with my family in the car when this car was a ticking Time bomb not even being aware of the Death trap on wheels. We ended having towed our home and then to then had to make a call next day and have it towed to Hyundai service center While we were driving this happen, where we heard two loud pops the gas gauge went down from 200 something to 80 engine lights came right up the backseats were heating up under my son seat in the back stated he felt waves as the backseat was getting hotter, we pulled over to a gas station and that’s when we had to call called O’Reillys and then we called a mechanic friend which stated that he ended up looking up the car and stated please pull over and get out car and called the Hyundai manufacture that there was a recall that’s the only way we found out other than that no prior incidents, then called the service technician of Hyundai i called amd complaint with the Honda manufacture corporate. They have failed to take the responsibility for this and they should be ashamed and take their accountability for this we could’ve died and anyone else around us on road as we drive this car daily The car was a higher risk of a ticking time bomb stated by the Hyundai service center technicians. this is an nere to miss accident narrowly avoid catastrophe

NHTSA ID

11668446

Incident

Jun 8, 2025

The car would excelerate while in park. While I was pressing the brakes the car would jerk forward, it would not just quietly idle. While driving the car would randomly speed up or slow down. Sometime it would sound like it was going to shut off and start vibrating.

NHTSA ID

11656443

Incident

Mar 8, 2025

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.

NHTSA ID

11645969

Incident

Feb 26, 2025

Mileage

47,000 mi

I have been to the dealership on three separate occasions due to the engine misfiring. Two ignition coils have been replaced so far and I recently returned to the dealership for the same issue. This time however, not only did the engine light come on but I went from a full tank to less than a quarter of a tank and the engine is making backfiring sounds. At that time the dealership said that they could not recreate the issue, I got my oil changed and went home. That was a week ago, I am back at the dealership today for the same thing; fuel dumping and backfiring sounds. While at the dealership today it turns out those backfiring noises were the fuel tank expanding so much so that it kept popping the seat up. They deemed the car unsafe to drive and it is currently at the dealership.

NHTSA ID

11603481

Incident

Jul 19, 2024

WAS PARKED IN BANK PARKING LOT. STARTED ENGINE, PLACED CAR IN REVERSE AND CAR ACCELERATED AT A VERY HIGH RATE OF SPEED. (LIKE I WAS IN A DRAG RACE!!) APPLIED BRAKES, WHICH DID NOT SLOW THE VEHICLE DOWN. DID NOT STOP UNTIL I RAN INTO A PARKED CAR. WHOLE INCIDENT TOOK JUST SECONDS. CAR HAD BEEN IN FOR REGULAR SERVICE AT THE DEALERS ON [XXX]. NOW HAS 16,597 MILES ON VEHICLE. CAR TO BE SERVICED AT RACHELS COLLISION, 720 S NOVA ROAD, DAYTONA BEACH, FL ON MONDAY [XXX]. IF I HAD NOT RAN INTO A PARKED CAR, I WOULD HAVE ENTERED [XXX] IN DAYTONA BEACH SHORES, FL WHICH WAS CROWDED WITH MOTORCYCLES.... FRIDAY NOON DURING BIKE WEEK. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11576439

Incident

Mar 8, 2024