I lost I cant get rid of this hesitation/stuttering while im driving I have a 98 f150 4x4 130,000 I have changed the plugs,wires,both coils maf sensor,intake manifold gaskets,i found a post on here on how to check the egr and dpfe.the egr is opening and closing as it should the dpfe had 4.98 volts on the forward hole and around 3.and some odd for the back hole so im guessing that is working.took it in had a diagnostic done no codes.got a can of carb cleaner sprayed the vacuum lines,all the rubber still no find.this will be the last 4.6 Ill ever own lol.oh yeah the fuel pump and filter is new this spring,plus I have lost fuel mileage went from 180-190 to a half to 130-140 to a half.
so if I missed a step in this puzzle can someone please let me know thanks.

 

Did you change all the coils or just a couple, the way you have it posted makes me wonder what you mean. If you bought a couple new coils did you check to make sure one of them isnt bad? If you have a coil that is not functioning properly that will give you a misfire.

The other thing I would check is make sure your spark plugs are gapped to the correct spec for your truck, and improperly gapped plug will also cause a misfire.

Did you check your injectors to make sure they are in their seating correctly? Another thing I noticed you saying is that you saying the fuel pump and filter are new, have you checked your fuel pressure to make sure that the fuel pump has the required pressure to deliver fuel to your injectors. You also stated the fuel filter is new, I assume your talking about the one on the rail? Did you use a Motorcraft filter or any aftermarket one

I know you said you sprayed the vac lines to see if there is a leak, but sometimes the little T's and elbows can crack and also cause a leak which would cause a misfire. You need to chase down each vacuum line and make sure the points that they are connected to on the engine are on solid and nothing had come loose.

There is a vacuum line that runs from the side of the engine and snakes all the way to the rear of the engine to a post just below the IAC It's a PIA the *** to look for, but make sure that line is connected and there are no leaks there. That line gets a lot of abuse and is prone to either wearing thru or coming loose

Re-check those things again and go from there.Only other thing that I could think of is that maybe the timing is off. And I sure hope that isnt the case, thats a PIA to go back in and do again just to correct it.

 

That symptom is from your Coil Over Plug being faulty minister in the spark plug holes,also vacuum leaks but it's rare the most common spot is the PCV boot.