Seems you have multiple issues going on. When is the last time you replaced routine maintenance items on your MINI? Such as filters, spark plugs, etc?
Here is some info on P1497:
http://forums.pelicanparts.com/bmw-mini/940120-vent-tube.html
For P0503, check and see which wheel speed sensor is your issue. You can specifically find out which one is an issue with the proper scan tool.