2016 Ford E250 5.4L Repeated P0201 Code After Injector and Coil Replacement - Misfire at 45mph
My 2016 Ford E250 with a 5.4L engine started exhibiting rough running at 45 mph, triggering the P0201 diagnostic code, which I initially interpreted as a cylinder #1 misfire. I replaced the spark plug, fuel injector, and spark coil for cylinder #1. The #1 plug was heavily carboned, likely due to prior misfiring. After these replacements, the truck ran smoothly for about 150 miles at highway speeds of 70-80 mph. However, when I resumed driving at 45–50 mph, the engine began bucking again. I then replaced the spark coil with an original OEM unit, hoping it was the issue—same result. The problem persists intermittently and only appears once the vehicle reaches operating temperature. The truck does not start or run smoothly until the engine has warmed up. Given that this is a recurring P0201 code related to cylinder #1 misfire, possible causes include: a faulty fuel injector, an open circuit in the wiring harness, a short in the wiring, or a malfunctioning Powertrain Control Module (PCM). I have ruled out simple component failure through replacement, but the intermittent nature suggests deeper electrical or sensor issues. Thank you for any insights, Walter Grzybowski.
Since this is an intermittent issue, diagnostic testing is essential—monitoring live data and attempting to reproduce the fault by physically manipulating connectors (wiggling, taping, heating) may help identify open or short circuits. Is your van still under warranty? Possible causes include: a bad fuel injector (most common), an open circuit in wiring, a short in wiring, or a faulty PCM. Read more: P0201 code explanation.