One problem related to emission control has been reported for the 2012 Audi A6. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2012 Audi A6 based on all problems reported for the 2012 A6.
Ran obd reader myself and at mechanic and found the following; p0456 evap emission control system (very small leak) | leak detected and p190f00 coolant pump for charge pressure cooler | electrical malfunction in load circuit. Mechanic informed that the vehicle needs a software update regarding the p0456 code as no leak was found. Also that only Audi performs this update. Regarding the p190f00 code informed me that there are several recalls regarding this issue as it has been causing some severe symptoms such as engine shaking, loss of power, squealing, whining noise near or at timing belt area at start up, delayed reaction at acceleration ( takes a while to reach desired speeds), temp gauge lowering despite warm up, warming of vehicle taking longer, unable to drive over 30-40mph and rpm won't go above 2000-2500 rpms. Acceleration is not as responsive as it should be.