Well, here's another update:
1. Sensor received and installed.
2. Full system check completed.
3. HPFP (High Pressure Fuel Pump) Failure - Needs replacement.
4. Will get reunited tomorrow (hopefully).
Will update again if there are more details on the work order once I pick her up. Sad that I am now in that small group of N55 owners with a low mileage HPFP failure. Glad that at least its been found and resolved without any runarounds. I started researching this failure and can't believe what some have had to go through.
Also as a side note, although my GT was driving fairly smooth and buttery, it did have some quirks that I just chalked up as intermittent and random slow throttle response. After I get a good week in I will provide another update if there is indeed a difference with the new HPFP.
2012 535i GT ED 1/9/2012