I've had the car for a couple years and it runs great except for a couple DTCs.
1. P0299...underboost from supercharger/turbocharger. I've not noticed any lack of performance, it runs pretty good in eco pro if I kick it and like gangbusters in Sport Plus. Wonder what's going on?
2. forgot the code, but it was something about the mass flow or manifold pressure sensor grounding out. Again, no issue with performance or fuel mileage (which is an outstanding ~26mpg around town/freeway, average 35mph.

The dealer exchanged for the OEM ECU and I ran it for 30 days usage and the mass flow DTC did not show up so they replaced the Dinan ECU and shrugged shoulders. Now the DTC P0299 pops up.

I discussed it with the service writer who noted that BMW no longer warranties or supplies Dinan tune/equipement, claiming it doesn't work well with the newer cars.

Any comments?