audi a6 2.7t

Possible plugged catalytic converter, have an exhaust shop check that out, or a week ignition, check the spark to make sure it is white in color, not an orange color.

Turbo charger inspection time have engine vacuum checked. and its time for a complete engine check up have your Audi 2.7 Turbo....scanned for codes at a local auto parts store many do this without charging any fee.

Have you looked at the condition of your air filter? Simple stuff first.

Please get ur intercooler checked