When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I brought my vehicle in for 5K mile maintenance on Wednesday(8/30/17). Once I drove the car off the lot, it's been struggling to build boost as the needle fluctuates while climbing through the 2K-4K RPMS when you hit about 7.5 psi or over. It's like if the turbo is no longer there. There is also an engine noise associated with this as well.
If the boost is fluctuating then it's the Vacuum Regulator which controls the wastegate. Take it back to the dealer and have them change it under your warranty.