Turbo maintenance????

[Lead_sled]

I’ll throw a few questions out there to see which options are best.

First, I recently changed my back pressure sensor and VGT actuator. This is on a CM871. Recently, a VGT actuator out of calibration error popped up. Since then, it’ll come on and go off. But most notable is that it seems like the turbo may be sticking. Sometimes it’ll spool to 37 psi and other times only to 20 psi. And sometimes on engine braking, the gauge will not rise. I’m going to remove the VGT actuator in the morning to see if the turbo arm is moving freely. If it’s moving freely, what do you think may be giving this error?

I’ve read that it could be a sticking turbo. Any maintenance for this issue?

If not, is it recommended to rebuild the turbo I currently have? If so, who is recommended for rebuilding? Or is a reman recommended directly from Cummins?

Thanks in advance.