My girlfirend has a 1.8T 04 plate A4 cab. she started it the other day and the engine management light came on and it started to run lumpy, as in sounding like it was a cylinder down. I have checked the core/coil plugs and found that the number 1 cylinder wasnt working. i have replaced with a genuine VAG part and it has sorted the issue, as in all of the cylinders appear now to be working and when you remove all of the the core plugs you can see it sparking and hear them clicking etc. however it is still running very lumpy when idling. It appears to cure when you give it some revs partly. Any ideas?