Turbo whisling

[Dcolumbia]

Had an actuator code, 2387 I think, when I took of the actuator the VG lever wouldn't budge. Obviously carbon build up on VG face and vanes. I had the used one that I purchased on e bay and being Sunday afternoon, no parts store open, I put it on to run the next 3 days. Now I have a whistle sound when boosting that gets louder with boost pressure. I believe it to be an exhaust leak where the turbo mounts since I had to reuse the gasket. Is this a possibility? Runs fine, better than with the old turbo, and I checked all the CAC hoses. No codes now. So will an exhaust leak at the turbo, the egr, or the exhaust pipe behind the turbo cause this whistling noise?