Hi , as with a large proportion of Audi customers including myself who have had this less that adequate EA189 NOX update carried out the problems can vary , but one seems to appear quite regularly and that is the cooling fan/fans running after the engine has stopped. Normally if your vehicle has or is in the middle of a DPF regeneration the fans run on for roughly 5 mins after engine stops to cool the engine bay as things get rather toastie . EGR problems seem to occur also , loss of power , engine sounds less refined. You won't get all that far with Audi as a few will lay testament to. A remap would probably put your Audi back to original ish state. Sorry to respond with this long essay. Kind regards Edd.