ok im kinda lost but maybe some of you can anwser my question my a/b light came on after adding amp to the car 01 a4 and i have friend that added a amp as well and his did the same thing but i have replace the ignitor in the d/s door already cause thats the code that the vag scanner gave me the first time i had it scanned then as soon as i turn the radio on the a/b light comes back now what maybe causing this and how can i add a amp to the car with out it interfering is it is indeed the cause of this issue

 

ttt come on people has no one added a amp to the stock system and had any issues like this