I had originally posted this in 4.6 & 5.4 modular troubleshooting. The truck has 83,000 and about 4,000 miles ago, I noticed a mis at idle and throughout all rpm's so I changed the plugs. The mis was still there. After changing the fuel filter, coils (used but newer), front O2 sensors, cleaned the mass air, and checked for vacuum leaks it's still there. The PCM isn't throwing any codes with my $100 code scanner so I took it to Ford last week thinking that they might be able to scan it more extensively but to no avail but they did recommend reprogramming the PCM per TSB so I did that as well. The mis is still there. Any suggestions would be appreciated.

 

Change Plug Wires, this happened to my 98 F150, had to change plugs and wires.

 

I don't have any wires. I've got COP's (coils on plugs). I've already changed the plugs (as written before). Anyone have any suggestions?

 

If it is missing, your Ford dealer should have been able to find it. If the CEL is not coming on no codes will be set, and no scan tool will find it. Take it back to the dealer and have them do a power balance test and injector flow test with their WDS. Also check fuel trim and O2 cycle rate.

 

Thanks 1toptech. I'll give that a shot and see what they come with.