Symptoms of a bad VGT

I just went through this. Symptoms would be only 1 stage on your jake/retarder, the turbo doesn't make the same spund at idle, and tirbo takes longer to spool. You'll notice it more in lower gears. Bad news is your turbo probably needs to be replaced. If its just the actuator its $1000 to replace but often its coking on the vanes that ruin the actuator. I just paid 6 grand for a new turbo. I drove about 5000 miles after it went out snd it ran just fine.

 

What year truck did you have the turbo replaced.

 

I have a similar problem with my Volvo Vnl 780 D13 2011 truck that has mysterious problems that nobody can resolve.
Truck simply stalls and loses the boost periodically and to a point that is impossible to drive. After many fuel filter changes and many trips to dealer and various repair shops nobody knows what it is. Not to mention truck has no codes on the dashboard. However with the Techtool I was able to detect some codes for J communication line that truck had. Any help is appreciated.