So I replaced my bad turbo with an aftermarket one from TurboChargerPros.com, I've driven 572 miles now and the other day I noticed a loud deep sound when I'm accelerating. It starts when the turbo gauge is in the space between white and yellow. It goes away when I push the turbo into yellow, then comes back with a dissipating sound to it when the turbo spools down from yellow to white. I'm thinking it's the wastegate. Any other ideas?