I had the RS6 almost down to an empty tank of gas earlier this afternoon and twice just before the gas station the car stumbled upon heavy acceleration.

Filled up the tank and car did not stumble again however I notice a slight whine coming from passenger side upon heavy acceleration sounds like maybe a vacuum hose or something from the turbo housing. Car seems to run fine but for this noise, want to get it sorted out & back to normal ASAP

Input appreciated on where to start the the troubleshooting process...thanks in advance