VGT Actuator Issues

[RMezaJr]

I've been getting fault codes related to the VGT Actuator, my guess is it's sticking. I've gone through the troubleshooting on Cummins Quickserve and its not an electrical issue. Recently had the return radiator hose blow out on me and did not refill using a vacuum pressure system. At first, I thought it may be carbon buildup but during inspection of the exhaust side of the turbo and the doser injector elbow pipe I found some white residue. I'm thinking it could be coolant from a leak in the EGR Cooler or fuel additives. Just trying to confirm my suspicions or get insight into what it could possibly be and how I can go about repairing the VGT Actuator issue. Was thinking I could purchase the {garbage product name removed by rawze} to clean the EGR, EGR Cooler and Turbo.

Thanks!