a4 1.8 2001 engine light on and blinking! READ !
 

I went to have my car smogged the other day and left the shop. As i got into the freeway entrance, the engine starts misfiring and the engine light comes on, blinking in the same time. Turned around and went home. Better safe that sorry. So once home, i read the codes and found out Cyl 1 & 2 misfiring.
Good electrician that i am, right away, i suspected the ignition coils of those cylinders. Switch them with cyl 3 & 4 coils and realize that the misfiring were following the coils. So i deducted that those coils were faulty.
i took those coils out and check for any sign of burn inside the coil where the spark plugs seat in the coil. I realize that the contacts were burned out.
I took a small round metal file and sand away those bad contacts.
Put the coils back in place after making sure that no more sign of burn contacts were visible. Engine started right up and took the car for a spin.
PROBLEM SOLVED !
Before you venture into buying new coils, make sure that you check those places.