2017 Hyundai Santa Fe Sport

My 2017 Hyundai Santa Fe Sport exhibits a documented mechanical failure under active code P0420 (Catalytic Converter Efficiency Below Threshold). This failure is the direct proximate consequence of a severe, long term manufacturing defect in the Theta II engine block, which has caused excessive oil consumption. Following the official 1,000 - mile diagnostic driving protocol completed on XXX, Keffer Hyundai (a Hyundai dealer located in [XXX]) service department officially confirmed the active code P0420 catalytic converter failure. They issued a formal written recommendation to replace the entire engine assembly but generated an out-of-pocket consumer estimate of $10,035. This case falls under the the terms of the Theta II Class Action Settlement which requires Hyundai to cover the defective engine block under the Lifetime Warranty Extension, along with any subsequent component damage (the Catalytic Converter) destroyed as a direct result of the engine's oil burning defect under the Lifetime Warranty Extension. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Campaign 9C2 was installed on this vehicle and the now the vehicle is a danger to drive. My wife refuses to drive it as it bucks and jerks as well as the gas mileage has decreased from 35 highway to 28 highway. The fuel trims are way off on cold starts and the transmission now searches for the correct gear. Shifting back and forth. Just a slight touch of the accelerator and the car seems to jump forward which makes stop and go driving almost impossible.

Following the completion of an official emissions recall software upgrade at Fitzgerald Auto Mall Countryside, Clearwater Florida, my 2017 Hyundai Santa Fe Sport (52,000 miles) now suffers from a severe loss of motive power and erratic transmission shifting/jerking during cold starts throughout day. The vehicle continues to hesitate during cold starts, making it impossible to safely accelerate from a stop into incoming traffic. I returned to dealership on 5/29/26 to address continued driving issues. The servicing dealership states they don't have a software fix and offer no mechanical fix. The dealership states they received an internal memo from Hyundai Corporate which instructed the dealership to tell affected owners to idle the vehicle for 1-3 minutes before driving to allow system adjustments. Forcing a consumer to wait out a dangerous powertrain defect in a running vehicle to avoid a roadway acceleration/loss accident is an unacceptable safety hazard. The manufacturers recall update has actively compromised the safe operation and motive control of this vehicle.

COMPONENT FAILED: Theta II 2.4L GDI engine connecting rod bearings. Vehicle has 95,000 miles. Engine available for inspection in [XXX] . SAFETY RISK: Engine knock + limp mode at 1500 RPM caused sudden loss of power on highway. Oil consumption 1L/700km risks catastrophic engine seizure while driving. CONFIRMED BY DEALER: Independent service center confirmed DTC P0010 from metal debris. Hyundai Motor America Case #42623761 confirmed recall coverage but refuses remedy. INSPECTION: Manufacturer aware via Case #42623761. Local Hyundai dealers non-responsive. No police/insurance inspection. WARNING SYMPTOMS: Engine knock started at ~94,000 miles. Check Engine Light with DTC P0010. Progressive oil consumption. Limp mode activated at 95,000 miles. HYUNDAI VIOLATION: Hyundai confirmed via email they refuse to honor Safety Recall 162 / Service Campaign 966 Lifetime Warranty for VIN [XXX] despite all symptoms matching recall description. Request NHTSA compel Hyundai to authorize Bearing Clearance Test and engine replacement. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Component: Engine (Theta II 2.4L GDI) / connecting rod bearing-related failure risk with abnormal internal oil loss. The vehicle is available for inspection upon request (engine, oil level condition, diagnostic history, and dealer records). Safety risk: While driving on the highway (approx. 70 mph), the vehicle displayed a low oil warning, and I experienced concern for potential engine seizure/stalling and sudden loss of power, which could cause a crash. I reduced speed and sought service. This condition presents an ongoing safety risk because sudden engine failure can occur without adequate warning. Dealer confirmation: The problem was confirmed by a Hyundai dealer. After a routine oil change, the low oil warning appeared within ~1,700 miles. A Hyundai service center inspected the vehicle and documented the engine was approximately 3 quarts low with no external leaks, indicating internal loss/engine deterioration rather than a leak. Hyundai then required additional steps (combustion chamber cleaning and monitored mileage), and the abnormal internal oil loss condition persisted. Manufacturer inspection: The vehicle has been inspected by Hyundai dealerships, and Hyundai performed campaign-related actions, including KSDS/ECM update (T3G) and later knock sensor replacement. No police or insurance inspection. No crash or injury occurred. Warning lamps/symptoms prior to failure: Prior symptoms included a Check Engine Lamp with DTC P1326 (KSDS-related) documented by Hyundai service in 2025, followed by continued abnormal internal engine condition. The low oil warning occurred while the vehicle was in motion (highway speed). The issue remains unresolved, and I do not feel the vehicle is safe to operate due to seizure/stall risk. Additional: I reported this as a safety defect because similar Theta II engine issues are widely reported and can result in stalling, seizure, or engine fire. Hyundai denied engine replacement assistance despite the documented condition.

I have maintained my car regularly. I use LOFSYNBLEND oil at 7500 mile intervals per car and oil manufacturer. At 70000 mile oil change the tech showed me that less than a quart of oil came out of the crankcase during the oil change. There were no visible leaks, no visible smoke coming out of the exhaust when I drove the car, and NO warning light. This was the first time that this issue was present to my knowledge. I am taking the vehicle to the dealer for an Official Oil Consumption Test.

The engine in my 2017 Hyundai Santa Fe Sport, specifically the 2.4L Theta II engine, failed and is available for inspection upon request. This failure caused the vehicle to stall unexpectedly while driving, creating a serious safety hazard due to the sudden loss of power and control. The issue has been diagnosed by a Hyundai dealership, which confirmed the engine requires replacement due to internal failure. The manufacturer has denied warranty coverage, alleging maintenance neglect by the previous owner. Prior to the failure, the Check Engine light illuminated, the vehicle began making knocking noises, and it experienced a loss of power before stalling.

The contact owns a 2017 Hyundai Santa Fe Sport. The contact stated while depressing the accelerator pedal and attempting to overtake another vehicle, the vehicle failed to immediately respond, and the vehicle decelerated. Additionally, the vehicle suddenly lost automotive power while driving at various speeds and decelerated. The vehicle was taken to the local dealer who could not duplicate the failure or determine the cause of the failure. The vehicle was not repaired. The manufacturer was notified of the failure, but no assistance was offered. The failure mileage was 10,000.

I was pulling onto I75 at 6:00am when my car started shuttering, making a clicking/ knocking noise and slowing way down. Thankfully I was able to make it onto the shoulder before causing an accident. I was unable to accelerate enough to go anywhere so I called a tow truck. My car is burning oil at an extremely fast rate. I have to get my oil refilled about every 7-10 days with the only warning of low oil being a flicker of my oil light. Continue to be shut down by Hyundai when we mention it. Everyone I know with this engine has had to have it replaced or get a new car. But Hyundai doesn’t want to do anything about mine. Currently sitting in their lot and they said it would be about a month before they would even look at it.

Driving down a 4 lane highway my car refused to accelerate and started shaking vigorously. My vehicles check engine light began to flask on and off. Had to pull off the high way and take the back roads the rest of the way home in fear that it would stop in the middle of the street. As we drove home, every time we would slow down or had to come to a stop the car would continue to shake and rattle with the check engine going and and off the rest of the way home. Took this to the dealership and they stated that I have a burnt exhaust valve on cylinder #2 along with needing a new catalytic converter and told me I should just replace the entire engine. I have 67k miles on a 2017 hyundai Santa Fe.