I have a F350 6.4l from 2008 (build date 09-2007).
after 41.000 mls the truck went in safe mode. I went to dealer. the come up with 4 code's P0404, P042e, P1335, P2263. all egr related the said.
to cure the problem the flashed the pcm. the truck drives like new again.
After about 2000 mls. the engine seems to loose a little bit of power.
a while later the engine went in fail safe mode again. back too dealer. almost there the engine stalls. the pick me up. put the truck on the computer. started the truck it run's on 4 cylinders (power balance one side) and the same fault code's. P0404, P042E, P1335, P2263. i was with the truck when the tech. put in a new reflash for pcm. (this time only one step higher, from - mc too md) he did nothing else too the truck. started the truck and it run on all 8 again. it smoked a little for about 10 mls afther that it run well. there is no oil consumption \ increases and no coolant consumption, i let the regeneration finish. anyone have any idea what this problem could be.

 

Did they check all the wiring connections to egr related parts?

 

electronics to the EGR...replace that and quit just doing a reflash.
EGR thottle body, acuator maybe.

 

I agree with what Scott said. It sounds to me like the dealer you are going to is taking the easy way out. I have a feeling you will have the same problem come up in another 1-2 thousand miles. There is a reason it keeps setting those codes after a while. Just my 2 cents and believe me it's all it's worth. Good luck and keep us posted if you ahve the problem again.

 

Thanks for the reactions. I know they have tested the egr valve (valve movement) and the throttle response. and they have checked the connectors and wiring.
i agree with Scott and Ed. and i am afraid it comes back. But why the engine is running well again if they start it after reprogramming. I do not understand that.