Not to correct the expert...
But P0101 is "MAF system performance" and my list has P1171 as "fuel system lean during acceleration". Codes 137,157 & 1171 all would occur if there is a problem with the fuel pump or a clogged fuel filter. Codes 101,137 & 157 all would occur if there was a vacuum leak. But if you look at all 4 codes, there is not a common denominator between them. I would ask the dealer to;
1. Perform a fuel pressure test.
2. Check for air leaks down stream of the MAF (MAF is the sensor on the side of the airbox), so this would include the thick black tube going from the airbox to the front center of the engine, the throttle body, intake gaskets, vacuum lines, EGR valve and tube, etc.

You might look for another dealer also, since these guys don't sound too bright.

Of course these are just my observations and I am not an expert

Kirk