Hello, I have got a 2001 52 reg Audi A4 with a 1.9TDi engine. The problem I have is that when the car is cold it misfires and then sometimes one of the cylinders cuts out.

I had a diagnostics run and two problems came back;

- 16685 P0301 - Cylinder 1 - Sparodic misfire detected
- 18074 P1666 - Valve for sporadic pump injector cylinder 1-N240: Electrical Malfunction

Now I have just had the injector on cylinder 1 replaced a week ago as I thought that was the problem but it hasnt made any difference. I dont think it is the injector itself as the car will start to misfire and sometimes recover and run fine, but sometimes the engine warning light will come on (orange triangle with an arrow around it, also comes on when the traction control is turned off) and it will run on three cylinders until I pull over and turn the engine off and then on again and it will run fine for a few minutes then start to misfire again.

Any suggestions what to look at/replace!?!?