STI coils are garbage... Audi coils suck but STI are alot worse. Coils aren't really a "maintenance" item so if the old one aren't misfiring leave them in

 

I have the same problem for about a 5 weeks now. I replaced the coils about 3 months ago (don't remember brand) I changed the alternator and belt with no luck. Mechanic checked the blue wire at the ecm that goes to the alternator he says that's the exiceter wire and trigers the regulator/alternator so he stripped a spot at the ecm then started car. with battery light on he put the test light on the blue wire battery and it trigered the alternator and the bettery light went off right away. now he thinks I need a new/used insterment cluster as this is what sends the signal through the blue wire to the alternator. so do you think he is right or should I change my coils again with a better brand?

 

zzaper,

I think you should change coils with genuien Audi parts. I put my old coils back (stock Audi coils), everything runs fine now. I returned those STI coils and already ordered 6 more genuien Audi coils. This is what I learned, always go with genuien Audi for any electrical realted parts.