HELP 370z goes into limp mode when passenger presses on floor board

[Cmillsap]

I am currently dealing with the weirdest problem I have experienced in owning a vehicle. The current issue I am having is when I have a passenger in the car if they press their foot down in the top right of the floor board the car will go into limp mode. It is only in one spot in the top right of the floor board and it will do it every time without fail. After the car goes into limp mode it throughs the P1606 code and then will reset and be drivable after about 10 minutes. I have done some exploring underneath the carpet and it have discovered the car has an aftermarket sound system and there are stereo wires running underneath the carpet exactly where the SPECIAL spot is. There is also a black wire that runs underneath the foam but do not know what it connects too. I have attached photos as well.

I can only assume it is some type of shortage that causes the car to do this but I do not know where to begin. Any advice at all is appreciated I’m tired of my passenger having to sit criss cross.