Anything and everything if you buy the pukka version.
Code read and clear.
Recode modules for extra features.
Logging and monitoring engine and other systems...
I swear by mine
Do you have a link to the exact one you have?! They'rs loads of different ones isn't there?
I have this one:
Ross-Tech Store: VCDS License with KII-USB Interface
Only works on "K-Line" vehicles (ie:B5 A4, 8L A3 etc) basically pre 2001. anything after will require a CAN interface such as:
Ross-Tech Store: VCDS License with Micro-CAN Interface
Or if you want to do Both K-Line AND CAN:
Ross-Tech Store: VCDS License with HEX-USB+CAN Interface