I have a 17 street glide with the sony 5000 and I put the thundermax in last week and its causing interference in the speakers. It is the wideband o2 sensors causing the problem. Thundermax said they have had customers with this issue before and they had to install a noise filter. So I bought a power noise filter from amazon that had decent reviews, put it on and it didnt help. I tried the constant 12v(yellow) and the acc 12v just to be safe, and neither helped the issue. All connections are tight, the ground is good. The system was fine before thundermax, and if I unplug the o2 harness the interference stops. Does anyone have any other suggestions? I also tried a rca ground loop isolator on both channels, and ferrite cores on the o2 harness and the rca cables with no effect.