Toyota Highlander misfire problems

Filed Jul 30, 2026 · Fuel system · AZ

On July 25, 2026, while driving my 2021 Toyota Highlander Hybrid at high speeds on the freeway, the vehicle experienced a sudden loss of drive power accompanied by a check engine light and a severe hybrid system error warning. The failure occurred without any prior warning or degradation in performance, forcing an immediate emergency maneuver through traffic to reach the shoulder. The vehicle was towed to Toyota of El Cajon for diagnostic evaluation. The dealership service invoice details the following findings: - Primary Failure: Primary fuel injector failure (direct injection system). - Diagnostic Behavior: The engine experienced severe cylinder misfires under load at freeway speeds when the direct injectors were commanded on. - System Impact: Engine misfires triggered a hard safety shutdown of the hybrid system, immediately cutting motive power to the wheels. - Repair Executed: Replacement of the failed fuel injector assembly Safety Concern: A primary fuel injector failure at highway speeds causes an instantaneous engine misfire under load, which immediately triggers a hard hybrid drive system shutdown. Cutting motive power suddenly in heavy traffic without advance warning creates an extreme hazard for rear-end collisions. I am requesting the federal safety agency document and investigate this failure mode and its automated system shutdown logic.

Filed Jul 11, 2026 · Engine · MA

The car is was a 2019 Toyota Highlander with approximately 125,000 miles. White Smoke started appearing in the exhaust. Quickly after that, the check engine light appeared and started blinking, meaning the engine was misfiring. We brought to the dealership, and they found that cylinder 4 of the engine was damaged (scoring on the inside of the cylinder wall). The engine was releasing metal particles in the oil. Further, the cylinder would not hold oil or coolant pressure, and was burning both oil and coolant. The only fix was to replace or rebuild the engine.

Filed Jun 3, 2026 · Engine · 151,000 miles · TX

The contact owns a 2017 Toyota Highlander. The contact stated that while driving at an undisclosed speed, the check engine warning light illuminated. The vehicle was taken to the dealer, who determined that the spark plugs needed replaced. The spark plugs were replaced by an independent mechanic, but the failure recurred. The vehicle was taken back to the independent mechanic, who retrieved diagnostic trouble codes P11F0 (Air-Fuel Ratio Imbalance) and P0305 (Misfire In Cylinder Number 5). The mechanic cleaned the fuel injectors, but the failure persisted. The contact was informed that the fuel injectors needed to be replaced. The vehicle was taken to a second dealer, Toyota of Cedar Park (5600 183A Toll Rd, Leander, TX 78641), who determined that cylinder #5 needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 151,000.

Filed Apr 20, 2026 · Engine, Fuel system · OK

Vehicle smells like fuel after engine toggles on and off between the hybrid system. This issue is intermittent, but when it is taken to the dealership they smell the fuel, with no luck duplicating the issue. I have also noticed when the smell is present the vehicle seems to run rough.

Filed Nov 26, 2025 · Engine, Transmission · NJ

1. The 3.5L V6 Engine (2GR-FE) failed due to the subsequent loss of lubrication caused by the rupture of the Oil Cooler Pipe (Rubber component), a manufacturing defect known under TSB T-SB-0201-11 (ZE2 Program). The failed engine is currently available for inspection by request at the independent service center before it is disposed of. 2. The defect causes a sudden and severe loss of engine oil. This creates a high probability of the engine seizing (losing all power) while driving at highway speeds, resulting in a complete loss of propulsion and placing occupants at severe risk of collision. 3. The failure was confirmed, not reproduced. The vehicle was initially diagnosed with misfire codes (P0300, P0301). New spark plugs and ignition coils were installed in an attempt to resolve the issue. As the misfire persisted, the mechanic performed a compression test, confirming catastrophic zero compression failure in cylinders 1 and 2. Professional diagnostics then revealed critical codes: P1603 (ECM Malfunction), P1604 (Startability Malfunction), and P1605 (Rough Idling). These codes confirm a severe internal engine issue, consistent with permanent damage sustained during the oil loss event caused by the ZE2 pipe defect in July 2024. 4. No, not physically inspected by the manufacturer. The manufacturer (Toyota Executive Office Case Manager) was provided with certified documentation of the failure, including the photo of the faulty pipe, maintenance records during our ownership, and the dealership purchase statement for the replacement part. Toyota refused to authorize a physical diagnostic inspection of the failed engine at a dealership before denying goodwill assistance. 5.Yes. The initial lubrication loss event on July 4, 2024, was preceded by a message displayed on the dashboard (followed by a second failure event in October 2025 indicated by a flashing Check Engine light and the Traction Control light).

Filed Aug 27, 2025 · Fuel system · UT

Today (8/26/2025) my wife experienced the engine light kicked on and that the AWD system needed to be checked. After fueling up it made knocking noises and difficulty starting, and took two times to start up. Ran an OBD scan and this is what it says, which is related to fuel pump low pressure. P117B - Fuel Pressure Sensor Circuit Range/Performance Severity - High Description - Indicates a problem with the fuel pressure sensor circuit, where the sensor's output signal is outside the expected range or performance criteria, leading to potential issues with fuel delivery or engine performance. P0174 - System Too Lean (Bank 2) Severity - High Description - Your engine is getting too much air and/or not enough fuel, this is known as a "Lean" condition. Excess oxygen is getting into your engine, which makes the combustion process less efficient. This could be caused by many different factors. Consequences of Continued Driving - Reduced power, Engine knocking, Rough idle

Filed Jul 29, 2025 · Transmission · WA

I’m reporting a drivetrain and engine performance issue affecting my 2019 Toyota Highlander, which I believe is related to Toyota's T-SB-0160-18, T-SB-0008-21, and Customer Support Program ZJC (CSP ZJC). My vehicle is exhibiting the same symptoms like: 1. Intermittent engine misfires (no consistent CEL, but noticeable during driving) 2. Hesitation and shuddering during light or moderate acceleration 3. Unintended surging/lunging — the vehicle will randomly jerk forward without throttle input 4. Whining noise under acceleration, which appears to come from the engine bay These symptoms negatively affect vehicle control and driver confidence, especially when merging, passing, or driving in traffic. The behavior is unpredictable and poses a potential safety hazard. After researching, I found that Toyota issued T-SB-0160-18 and T-SB-0008-21 for this engine, acknowledging similar performance issues due to valve train irregularities and ECM programming. Toyota also released Customer Support Program ZJC, offering limited support to some VINs. However, despite my vehicle showing the same symptoms, it is not included in the CSP, and Toyota has not offered assistance without out-of-pocket costs. This issue appears to be more widespread than Toyota’s internal VIN list suggests. Many Highlander owners have reported the same issues online, and I believe Toyota should take responsibility for correcting these performance defects under a recall, not a limited CSP. I respectfully request that the federal safety agency investigate the scope and validity of Toyota's CSP ZJC and TSBs related to the 2GR-FKS engine and push Toyota to expand CSP ZJC or issue a formal recall to cover all affected vehicles based on symptoms, not just VINs

Filed Jun 19, 2025 · Electrical · NJ

Car is shaking heavily when stopped. Several misfires while engaging the brakes. Mechanic is telling me that he has seen many vehicles of this model with faulty purge valves.

Filed Feb 19, 2025 · Electrical, Engine · MO

[XXX] Dear staff there are other people complaining of ENGINE MISFIRE also [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Feb 17, 2025 · Acceleration, Engine · MO

ENGINE CHECK LIGHT coming on constantly Cylinder 3 misfire reported under DIAGNOSTICS of ADVANCE AUTOPARTS 500 Rte 291, Lee's Summit, MO 64063 another workshop said NO MISFIRE however now it says Engine Misfire 1, 3, 5, 6 4 cylinders misfiring as per diagnostic on 02/15/2025