2007 F350 with 4" exhaust (no other mods)
105K miles

This started off as a periodic smoke and loss of power while towing. Now it has gotten much, much worse.

Now it does it whether or not I'm pulling a trailer. Here is what its not:
- Turbo (took it apart, cleaned it, nothing major found)
- EGR (cleaned it)
- Injector
- Filters (all replaced, air, oil, fuel, etc)
- Computer has been flashed
- Hoses or connections (vacuum is good)

It doesn't do it every time I accellerate, but most times. We put it on the dyno with the computer hooked up and it doesn't show anything wrong. We thought it had to be a sensor down the line, so we swapped all of them out and still the same result.

HELP!!!

 

What do you mean that the computer has been reflashed? Has the ECU been updated by the dealership, or does/has the truck had a performance tuner installed? Any CELs coming on?

 

The ECU has been updated by a motorcraft repair shop. Periodically there will be an exhaust related light.

 

Replace the EGR valve. Ford doesn't recommend cleaning anymore. Bet if you check the valve again it's sooted up. Good luck!

 

Delete the EGR valve, you'll thank yourself in the future.

 

Of course they don't... they make no money off of you cleaning them.

 

I dunno if this applies to this engine or not, would need a tech guy to verify, but my first thought is an intake leak, (i.e., cracked pipe on the pressurized side of turbo). If the intake bleeds metered air, then the mixture goes rich.
You said you checked hoses; did you check just the little ones or did you check the big intake pipes?

 

I lost power on take off and started to puff a little black smoke. Upon further investigation, they found the pcm to be bad