vladc77

I am wondering if someone can help to identify if the amplifier is bad that I have. I installed IPod integration Kit for Mercedes GL, 2007. I also added amplifier with part number A 204 870 3994. Everything works well except Amplifier. As soon as add it to the system, the sound becomes louder but distorted and not listenable. I believe the amplifier is not working correctly. I am wondering if it is possible to fix somehow. Maybe, it requires Star coding for that amplifier. I am looking for any advice. Thank you in advance.