2003 Ford F150 5.4L 2v
Long story short, purchased in May 2022 from the original owner. Had no maintenance history but truck appeared to be very well kept and clean. Currently has 146K miles. Truck was getting between 10.5 and 11 MPG but otherwise ran well. I had the spark plugs replaced in Nov of 2022. In Dec 2022 the Service Engine Soon light came on for the first time, Misfire Cyl 4 (P0304). Since then, about every 2 weeks of so the Serve engine soon light comes on and stays on until reset, same code! The cylinder has been checked for compression, spark plug has been replaced again, the coil has been swapped with two other cylinders, the code remains the same and does not follow the coil, have replaced the fuel injector and the coil. Was told by a ford truck specialist, over the phone (can't get in to see him, as he is 40 miles away and has a 6-8 week waiting list to get in), to try replacing the fuel injector connector, as he has had the same thing happen to a same year and engine Expedition, on the same cylinder and it turned out that the wires at the connector were bad. Any thoughts? I am a subscriber and have learned a lot from you. I am however way over my head on figuring or helping my mechanic figure this one out.
Well yeah the connectors have been known to go bad and that's exactly what will happen. Since you tried everything else the connector is bad. Are the wiring is bad somewhere or the driver circuit in the computer that controls it is bad
