Hi. My 2008 A5 3.0tdi has developed a problem. I first noticed a sudden loss of power when driving you could feel the car slowing down, then tonight it was like surging when idling took it for a spin and was ok at first but then it felt like it was pulsing so I pulled in and the car stopped. It turned over slowly then started. Could this be egr issues do think it’s a fuel filter as the car has a full Audi service history so should have been changed.