Cylinder 1 Misfire Detected

My vehicle has experienced a recurring cylinder 1 misfire (code P0301) over approximately two years. Ignition coils and spark plugs on cylinder 1 were replaced multiple times by different repair shops, but the misfire repeatedly returned, sometimes within months, sometimes within about a year. Wiring and injector testing was also performed and ruled out as the cause. A mechanic ultimately performed a leak-down/compression test and borescope inspection and found a compression leak located in the cylinder wall between cylinders 1 and 2, indicating internal engine damage. I was advised that this is not economically repairable and would require a full engine replacement. After researching this…

My 2017 ford edge titanium 2.0 ecoboost has lost power and my coolant warning goes on. My check engine light stays on OBD scanner states p0301 cylinder one misfire. I have taken the spark plug out of cylinder 1 and did a coolant compression test and can clearly see coolant leaking onto cylinder 1. I do have a video of this as well.

For the past year, I have been dealing with a recurring check engine light on my Ford Fusion related to Diagnostic Trouble Code P0301 – Cylinder 1 Misfire. Despite multiple repair attempts by qualified mechanics, the issue continues to return, leaving me with mounting repair bills, lost confidence in my vehicle, and serious concerns about its reliability and safety. Every time the check engine light has appeared, I have taken my vehicle in for diagnosis and repair. Each time, I was assured the problem had been fixed. However, the repair would only last anywhere from a week to a month before the exact same code would return. I have now experienced this issue on August 8 2025, January 9 2026…

Head gasket blew, and car overheated immediately on the freeway, with no warning signs, and at only 43,000 miles when a failure like this should not occur. Had to find a place to pull over and be towed to avoid more engine damage. Both independent mechanic and Ford dealership has confirmed this. Official diagnosis is "Remove and replace cylinder head assembly and replace head gasket – coolant intrusion cylinder 1, P0316, P0301.” Apparently it's a known issue with this particular engine and has a pending lawsuit.

Recently my car's check engine light and the message "Service Stabilitrak" started coming up on my car, then my car started shaking while idling. I quickly took the car to my mechanic who assessed it, replaced my spark plugs, which did not solve the issue, and recommended I go to the dealership. In between these appointments my car was consistently shaking while idling and I would have difficulties accelerating especially after coming to a complete stop and often while making turns, this worsened after adding fuel to my car. The nearest Chevrolet dealership did a compression test and found that the psi in cylinder 1 was only 85, while the rest of the cylinders are 180 psi. They reported…

Vehicle “slams” into gear and goes into “limp” mode. RPM’s increase dramatically and speed accelerate ration is very low. Check engine light on and several U codes show. And P0301

I am reporting recurring engine misfires involving my 2025 Ford Explorer Platinum equipped with the 2.3L EcoBoost engine. The vehicle currently has approximately 15,700 miles. The first incident occurred approximately five months ago. The check-engine warning appeared and the vehicle was diagnosed by an authorized Ford dealership with DTC P0303, indicating a cylinder 3 misfire. The cylinder 3 spark plug was replaced. A second misfire subsequently occurred at approximately 15,700 miles. The vehicle again exhibited an engine misfire/check-engine warning and was transported through Ford Roadside Assistance for service. An authorized Ford dealership diagnosed DTC P0301, indicating a cylinder 1…

The engine's cylinder head/valve train has failed internally, allowing combustion gases to enter the cooling system — confirmed via a chemical block test performed by a master automotive technician on November 29, 2024, which verified combustion gases present in the coolant. This is a widely documented defect on this engine and model year, related to valve seat erosion in the cylinder head. Symptoms first appeared in June 2018 as an unusual higher-pitched, stressed sound from the engine. Over time this progressed to recurring, confirmed misfires on cylinders 1, 2, 3, and 5 (diagnostic codes P0300, P0301, P0302, P0303, P0305) and a mixture control fault (P219B). The check engine light has…

P0301 Error - Cylinder 1 Misfire. First the Check Engine light and Service Stabilitrack light turn on. Then seconds later, the car began to violently shake and sometimes the gas will not go resulting in the car being stuck in the middle of the road for about 60 seconds before moving again in stop-and-go traffic. These warning lights turn off and on. The dealer says this is the result of a plastic piece breaking due to general wear-and-tear and the only solutions are to replace the pistons or replace the whole engine. Multiple smaller repair shops say this is a known issue and it doesn't have any open recalls. [XXX] [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA)…

While driving my 2018 Silverado, the 5.4L, 327c.i. engine began idling very rough, shaking and periodically stalling. The check engine light began blinking and it threw codes PO308 & PO301. After compression test & new plugs/wires, it was found that the injectors had open circuits on injector #'s 1 & 8. The only way to replace the injector is through the bank. In this case both banks 1 & 2 were affected. Cylinder #1 is through bank #1 & cylinder #8 is through bank # 2. After removing the intake manifolds and injectors, it was found that the injectors were not providing fuel to the engine causing a misfire on 2 random cylinders #1 & #8. Called the dealer to order parts and discovered they…