I have a 2004 f-150 5.4 Trition v8 and recently i had misfires on 5 and 6 come up. After I changed out the coils and injectors on all the cylinders the misfire would still come up. Im looking for some more help on where to go from here.
Did you replace the spark plugs as well? Since 5 and 6 are side by side on this engine, maybe you have a head gasket failing. You need to run a compression test on 5 and 6 at least but do them all so you know the total condition. Run a dry and wet test. If 5 and 6 are both lower than the rest, there is a good chance the head gasket failed between them causing a misfire.
I did change the plugs as well but ill try doing a compression test, thanks
You might also hook up a noid light to #5 and #6 injector plugs and see if it’s flashing when the engine is idling