Table 1 shows one common other fuel system related problems of the 2021 Hyundai Sonata.
| Problem Category | Number of Problems |
|---|---|
| Other Fuel System problems |
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 The failed component has been replaced by the dealer, but the manufacturer refused to replace the coolant-poisoned oxygen (O2) sensors, leaving the vehicle in a technically compromised state.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.
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.
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).
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.
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.
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.
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.
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.
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.
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 1/4/24. Now has 16,597 miles on vehicle. Car to be serviced at rachels collision, 720 s nova road, daytona beach, FL on Monday 3/11. If I had not ran into a parked car, I would have entered aia in daytona beach shores, FL which was crowded with motorcycles. . . . Friday noon during bike week.
Battery keeps dying randomly. Approximately once every other week and I drive 12k miles a year… dealership reassures me it’s find. Found numerous reports of other sonota hybrid users experiencing a similar issue.
When attempting to pass other vehicles or under quick acceleration such as an on ramp to the highway, the vehicle will experience a sudden loss of power and oil pressure resulting in a fail safe mode which limits your acceleration and causes a sudden decrease in speed and velocity. The issue results in the oil pressure light illuminating and requires the vehicle to be stopped and completely turned off to reset then once turned back on, the problem is “gone” until a sudden acceleration occurs again, which results in the same issue happening. There is a current recall out for similar models but my VIN is not listed. I have approximately 50k miles on the car, and am the first owner.
When I arrived in the parking lot and selected the r (reverse), the vehicle stayed in the d (drive) although that it was moving backwards and was able to park it. The shift selector was stuck in drive (drive) leaving the vehicle on but not operational. After several attempts to allow the vehicle to cool and the battery to reset, (30 minutes_ later), the car started and took the vehicle to be serviced. The vehicle technician said they had a difficult time diagnosing the vehicle because it was giving different codes. They said that while testing they found the transmission shift selector module was damaged. Not physically but electronically damaged. They also stated that the car could have other problems but that they needed to replace the module first because it could be the cause of the other errors.
My car barely has 11,000 miles and just the other day it had about 20miles left of gas but as I was driving on the road it started to feel and seem like it was about to die on me, also the front wipers are not well restrained with the vehicle you can tell by the way it moves when wipers are on. . . . Also most of the signals be it if something is in front of me and the signal goes off but theres nothing there . . . Also when im backing up sometimes the car itself will force stop as if something is in the way . . . But again nothing is there at all . . . It happens every few days . . . . I just purchased this car . . And really thinking it was worst mistake w all these issues already.
Incident sounds similar to those experienced with the dual clutch transmissions. November 2022, all of the vehicle warning lights were on and remained on. The vehicle would not move and the transmission selector/shifter was locked in place. Working with the local service/dealership, the vehicle was repaired after 3 weeks with a new transmission shift actuator (or possibly other part). Similarity in the experience and possibility of risk with little information about trends or others in similar situations or resolution. We've had another (same make/model/year) vehicle present similar circumstances.
Oct engine stalled exiting i95 in kittery maine. Engine light flashed but did not stay on. Was able to get to safe place but car would not go more than 15mph. Hampton huyndai reported mis-fire but stated it cleared on its own. Oct 17th: engine stalled on highway ramp to i495, nearly causing me to be rear ended by other vehicles. Car would not go more than 15 mph. Engine light stayed on. Towed car to key salem Hyundai, defective injectors, warrantee repair. Oct 23rd: car stalls on i93, was able to take immediate exit and turn engine off. Engine light flashed but did not stay on. Took car in to salem dealership on oct 24th, no code found. Oct 25th: car stalls again on city street. Light stays on, salem dealership replaces cat. Convrtr between oct 26th through Nov 4th. Nov 9th: car stalls again on city street. Light stays on, currently in salem dealership. This is a safety issue, in two cases already this car has nearly gotten me in an accident on the highway. I am seeking arbitration for replacement. I am scared to drive this vehicle. I will have a third invoice pending this next repair.
Unknown.