Code reader says coil A is bad. what # cylinder is that? 2004 F-150 4.6 L

p1262 is sometimes just an anomoly.

spark plug , coil pak ?? bad or slow to die

I would start with the spark plug, then plug wire.

If all 6 coils are factory original,
replace them all.
You may have a 304 & it may not even
be the bad coil or you have several bad.
Change sprk plugs every 3 year
Change front O2 Sensors at 100,000

This could mean that you have a bad/fouled plug or plugs, bad plug wires, bad coil packs, a misbehaving fuel injector, or a scad of other things.

I'd try new plugs and wires first. It's the cheapest fix and maybe the most likely answer.

I wonder though. It seems that I've seen codes that tell you exactly which cylinders
are not firing correctly. Your code seems to indicate more than one cylinder. That still points
to the things I mentioned above, but also strengthens the coil pack theory, as they feed more than one plug.

Not sure what year you have but you may have a bad plug wire, bad plug, or coil pack for that cylinder. A plug is cheap and easy to try. I think you can buy single wires from a ford dealer also to try and then you are getting down to the coil pack. You really need to have a scanner to help you with this and not just a code reader.

Coil pack going bad, spark plug wire going bad, or spark plug going bad.

Put a scanner or code reader on it, and get the code,
that set the MIL Lamp on the dash,diagnose from there.

Most likely a bad COP Ignition Coil

You can unplug EGR Valve,plug hoses and test drive to
confirm that issue,if you get an EGR Code

Cylinders from front to back

Pass Side 1,2,3,4,
Drivers Side 5,6,7,8

Coils about $60,00 at auto parts store, do yourself

You will get PO301 thru PO308
Last number is the cylinder #

Try swapping the defective coil and see if the fault moves with the coil, if not you have defective circuits to the coil....When the scanner tells you a story, its only half the story....It reads faults in an entire circuit and it will identify that circuit, but maybe not the exact problem....Regards Johngee10

Code P1399 is specific to Honda - it is an error code for "multiple variable misfires detected". P0301-P0304 are common OBDC codes for all cars, specifically "misfire in cylinder X".

You will get the P0301-P0304 codes on your OBDC reader when you plug it in (if actually errors), but will only find the P1399 if you select Honda as the manufacturer.

Just got these errors today on my CRV 2000. Now I have to figure out what is causing two of the cylinders to misfire.