I have a 2000 f150 5.4L with a miss fire, it is always cylinder 1, sometimes 2 and 4. I replaced plugs, coils and injectors. I recently bought the truck, cheap with the miss. The previous owner replaced DPFE sensor, EGR valve, IAC, all 4 O2 sensors, and most of the vacuum lines. I sometimes get a lean or rich code on bank 2 with the miss fire codes. It is not as bad when engine is cold, or when under load, but when warm at idle or in overdrive it is real noticeable. I am out of Ideas any help is greatly appreciated.

 

Some comments.
Cylinders 1,2 and 4 are bank 1.
Your other codes are for cylinders 5 through 8 bank 2 if your accurate.
List all the codes you see.
With what you have provided, it does not make a lot of sense except you still have an air leak some place.
Normaly an air leak won't take out specific cylinders.
For me, I would do a through check out for more than one issue at the same time by using a Scanner that can look at live data to get some place to start.
Is the fuel pressure correct at the fuel rails?
It may even remotely be the PCM or it's connector is loose.
You have to go about it from a technical basis or you spend money trying to get lucky which hasn't happened yet.
Seems the last owner did not know what to do either.
Good luck.

 

Update: Started to take off in truck and and lost all power, pushing throttle made no change in RPM's, the truck would not even pull itself. I turned it off and restarted it, giving me power again for about a minute. By the time I got back home, only 2 mile trip, the lower converter on bank 2 was glowing. I assumed because of miss fire but my codes have only been for cylinders in bank 1. I am thinking maybe PCM now?

 

Welcome to FTE BLUEOVALBS,

First of all list ALL the codes that you are getting.
Second - stop throwing parts at this truck!

Also, it seems that the PO did little in preventative maintenance on
this truck.

What is the mileage? How long ago did you purchase the truck?

Stepping back to locate the problem using a systematic approach is a must
like Bluegrass mentioned.

Check again for air leaks after the MAF sensor.

Remember to disconnect the NEG battery cable when replacing any sensor.

BLUEGRASS, could he have a damaged/clogged CAT?

 

From what i'm reading, the cat overheat indicates one or more cylinders failed ignition.
This sends a lot of raw gas into the cats where it burns. The injection is still working.
Seeing a bright cat on it's (outside protection case) means the internal temperature has gone well over 1000 degrees.
This melts the substrate that has the reaction coating and could set a fire to the under carrage if there is anything to burn.
The result is a total collapse to the point of nearly plugging the inlet/outlet and causing the loss of power not only from the missing cylinders but from those that are still firing.
The cats are not meant to run much hotter than about 700 degrees.
With temps this high the tip of the OX sensor also can melt and the rear can get contaminated.
A PCM coil switch can be the cause that starts all this going.
A way to look at the possibility is with an ohm meter looking back toward the PCM switch.
It should read about 10,000 ohms +/-.
If open or a very low resistance, the switch is bad and or the board is burnt.
If this is the case, the PCM has to be replaced, and reprogrammed along with 2 keys if the vehichle has the PATS system.
Unfortunely the cost of these repairs on top of the cats and OX sensors mounts up to big bucks your stuck with because a dealer normally has to do the work.
Ford owns the software and access so you have no choice.
It is possible for an outside vendor to supply this but if you have issues with the software version or equippage that's another issue on top of it all.
Sorry it's not good news but this is how it can go. Not to often but it does happen.
Moral of story, never never keep running an engine with cylinder/s out once you feel it right away or see a flashing CEL . This saves the cats, hopefully and limits expenses.
Doing the repair, always fix the missfire first, then attend to the cats.
If you see a code 420 after the missfire is fixed it means the cats/sensors have been damages beyond limits.
If you run after the missfire is fixed with out attending the cats, either you will be down on power, and or have poor fuel mileage.
If this goes on long enough the PCM will clear the 420 code because it is no longer usefull. The only way to see it again is do a clear on the PCM to force it to run all diagnostices and see the cat failure as a new code again.
Good luck.