I have had my C220d since february- every 500-1000 miles the engine starts to stutter a little, then the EDC light comes on and the 'stuttering' gets so bad you cant really drive- engine cutting in and out a few times a second. If i pull over, stop the engine and restart the problem goes away for a long period before coming back. What could be causing this? I'm not sure if the car is underpowered at the moment- i have nothing to compare it to, but it does seem slugglish the rest of the time.

Advice would be much appreciated