Hi, I have an issue with my a5 3.0 tdi quattro. The engine management system light came on and the car seemed slow, like it was limiting the speed to a max of around 70mph but with very poor acceleration. I then refilled with deisel and this seemed to go away. Now the issue has come back again and is also now accompanied by the emission control system light.

I don't think it's the dpf filter as that was replaced a few months back and when i had the dpf issue the speed was again limited but more to 20 mph. the dpf light isn't showing. What could this be and am i ok to drive it home (slowly) as i'm 200 miles from home. Does it sound like it could be costly as the dpf cost me £1700, i recently paid almost £800 for a service with a few minor repairs and i'm now running out of cash to be able to own this car!!

Any advice greatly appreciated. Really worried that this could be serious.