P0172 (M) - 1/1 Fuel System Rich - A rich air/fuel mixture has been indicated by an abnormally lean correction factor.
P0132 (M) - 1/1 O2 Sensor Shorted To Voltage - Oxygen sensor input voltage maintained above normal
What sensor are you replacing it with? You should only use NGK/NTK or OEM sensors in these cars, they don't like anything else.
P2503 - Charging System Voltage Low - Charging system voltage below minimum acceptable voltage.
P0622 (G) - Generator Field Not Switching Properly - An open or shorted condition detected in the generator field control circuit.
From the looks of it you need a new alternator. Check all the connections to it first though.
2011 BMW 335xi (e92)
- Black Sapphire Metalic w/ Coral Red Interior