Depends what part of the wastegate you are talking about.
But i took mine back to the dealer while it was still ynder the 3 month warranty and had 3 or so Sanjays sit in the car and try to deny even being able to hear it (this was before i put the 3"
tbe on so wasnt as noticeable).
I hate to say this but you may be fighting an uphill battle and its something you may have to just get used to. You would prob spend less money upgrading the turbo to a VF series than trying to pin point and fix the issue.