tjmillerjr

I have this issue as well. Occurs at most any speed above 40mph. If I accelerate or decelerate it goes away. It’s not the ANC. It is more noticeable if the windows are down and I’m driving down a small road with buildings. The reverb really makes it obvious. Radio on or off, blue tooth on or off, tape over speakers or not, it just does it all the time. Dealership couldn’t find an issue last week, but kept it all day and admitted they could hear the noise. They had no idea what the issue was at that time. Hope the emissions cable turns out to be the fix so I can tell my dealer. If not this might be the first and last GMC I own and the shortest time I own a vehicle. My 5 hour one way Christmas trip nearly made me go insane.