We took it to a desile mechanic and he could not duplicate it. replaced both batteries, they went through all the wiring, The horn does not work, changed the alternator. What else ??????

The check engine light was on for about 20 minutes and it only does it when I speed up.

Once the smoke finally blows out it will run fine. Until I stop again and take off. ?!? It is a 6.0 power stroke

Was told to check inline filter and don' find one

Motor is real sluggish and have to stop and restart the motor. The its fine for a while until it does it again. Seems like it only does when it's rainy weather

Replaced intake gaskets, no change. switched COP's and no change.

Truck does not drive or shift differently. Will it harm the truck to keep driving it?

all light\s -air -etc work just no dash lights & when I stop At Stop sign it pulls away in 2nd gear!!!

In two weeks time, my truck has gotten worse. First was glow plug light staying on and no fuel flow when trying to start. Then last week started shutting off after first get going. Problem is getting worse. If I get all lights on dash (water in fuel light comes on and cycles off), glow plug light goes out and truck starts. If water in fuel light doesn't cycle on, glow plug light stays on, and truck will not push fuel to start. Cycle key over, doesn't always work, sometimes works. 2 nights ago, check engine light finally came on, drew 7 codes, which I don't have here as I type this. New GPR installed today though, so it isn't that now.

2 new batt ,new fuel filters new oil filters checked and confirmed fuel at top engine mount checked ficm 48 volt ,had starter benched tested good and replaced altinator also checked all pulleys cranks really slughish and sound like something holding it from turning over

When I drive down the road I will hear a grind sound like 4 wheel wants to kick in , if I turn on the 4 wheel drive it will stop. I have to drive it in 4 wheel drive or it will do this all the time it is set on auto on the hubs, they have been just replaced, I no the pump is good or the 4 wheel would not kick in. What would cause this to do this a short in the switch on the dash or is their any other part iI should check.

All other states "ready". I have performed 5 drive cycles as per recommended in the owners manual, another from the ford site, and another found on you tube as well as "just drive it some more" as the smog shop recommends. NO trouble codes have listed.
What's next?

Can someone with a positive traction rear end F-250 give me the number off of the tag that is attached to the rear end housing. The parts guy at the dealership says he needs the number to look up the needed parts (positrac carrier)

I have a fault cod saying misfire on # 9 cylinder, and don't want to take all of the coils and plugs out to find the bad one. Plus I have replaced 1 coil and plug already do to it ejecting from the Head.

I just replaced all 3 exhaust temp sensors last week.
What the hell now????

My truck has issues with sputtering when pulling uphill. I've replaced the erg valve but the problem persists. I'm getting the following codes. P0401, P0402, P0603. KAM error. It's as if the erg valve is being told to open and close back and forth which causes the sputter. A ford tech saw this behavior during a test. The test showed the erg valve being told to open then close in rapid succession but the erg valve couldn't k.

I do not believe its a bad alignment issue because the truck pulls to either direction while my hand is fixed on the wheel. Recently it was so bad that my steering wheel was rocking back and forth causing the vehicle to shake in a manner that was unfit to drive. This problem seems to come and go and is not consistent throughout the whole drive. It is more apparent at the start of the day and after it sits for sometime. I believe it could be a loose/warn tie rod end maybe even an end-link or a worn/bad ball joint. Not sure how to diagnose any help or insight would be awesome.

This is intermittent problem and check engine light comes on. This happens before engine warms up.

its a Ford F-250 Super Duty Lariat Diesel 4WD