I know it is "turbo underboost" but what is the fix and should I be concerned.Truck has 79k 95% trailer towing about 18k gcvw.It has happened about three times while towing usually at a low rpm(truck has 373 gears)so my guess would be the engine is either"lugging" or the turbo is faltering.Thanks in advance.
Jim

 

6.0's are notorious for failing turbos there is a very good chance if you have your turbo replaced the turbo the code and problem will go away

 

sounds like the vains in the turbo could be sticking only way to fix that (if thats the case) would be to change the turbo.
also when it under boosts do you loose power and have excessive smoke (black)

 

Replacement of the turbo is not necessary.

Take the turbo halves apart and clean the carbon and crap off the unison ring and CHRA. If they are pitted/rusted or the actuator hole is oblonged - CHRA and unison ring should be replaced.

 

Just had mine replaced along with a larger drain tube .
she was blowing oil down the pipe resulting in "white smoke "

 

That larger drain tube is a big crock of ****.

I ordered a complete reman (Turbo to oil pan) 6.0, and it came with the small (old style) drain tube installed.

I personally don't think it does squat, but I put 'em on if they've got the little tube and I'm workin on 'em.

 

seriously , I got the turbo douched and swapped out the drain tube .....no more oil running down pipe and the white smoke dissapeared