Replaced plugs, coils, fuel injectors. Ran fine for a few miles started missing again. What else can it be? Crankshaft sensor? Also what is the proper thread depth for the spark plugs?

 

If you have the correct spark plugs, there should be no question regarding thread depth.
If you are referring to the spark plug gap, that info is in your owner's manual. If you don't have a copy you can view a copy on line and copy the specifications as needed.

Once you sure the correct plugs have been installed with the correct gap, look very carefully at the part of the coil that goes over the spark plug..
What you are looking for is what is called carbon tracking where the electrical current goes to ground around the outside of the plug instead of down through the plug to the gap and igniting the fuel mixture. Let us know what you find , thanks.

 

I will check them again. It was sitting for over a year, thinking it could also be bad fuel or wat in the fuel. It was running awesome, then misfire again.

 

Changed plugs, checked gap. Ran great for about 1/2 mile. Still misfire. Where to go from hear?

 

Is this something where it runs well while cold then as it gets warm it begins to misfire?

 

Maybe, I'll have to work on it. It didn't even get warm this time.

 

Usually,,,,,when we suspect something , the idea is to set out to verify it.

No matter how many parts we change , if we suspect a possible fuel contamination problem, that should be eliminated before changing anything.

Can you check if there is any water in the fuel/filter ? Stale fuel?
If the misfire is constant, remove the plugs and look for a fouled plug to help isolate which cyl may be having a problem.
Once we know whether it is a particular cyl or multiple cyls , the answer to that will determine where we go next.
If you had the equip do do this , it would save some time and work. Since (I believe) we don't have that equip we may be able to come up with something by examining the plugs.

 

It's a p300 random misfire. It doesn't matter if it's cold or hot. If I reset the computer ( unhook battery), it runs perfect, but then gets random misfire. Went to dealer and this thing has 5 open recalls, including ECU update. I'll go from there once that is taken care of.