Cant say I ever dug in there, but with some dedication & determination I know it can be done (encouraging useless words)

Correct 100% they came from Japan like that, disconnected or disabled, rather rare to see one still connected with the Butterfly in the System still   mine was still plugged in and if you drove with the seats down & Cover off you could hear & see it activate at certain RPM's (I owned a BG5 Rev C GTB)   Basically a "quiet" mode for street & LOUD for Fast @ WOT   I'm not entirely sure of the Trigger or signal source   & yeah, 'stock' exhaust' but unlikely the OEM rear section that made use of this (Twin Pipes?)

Hope this isn't too dead of a thread but I need help. I have the dreaded code 66 and I'm at a completely loss.. took my BBoD apart 1 line by line and blew out / replaced hoses. Still getting the same CEL. It feels like any time it's under load it just hits a road block and starves it's self of air.    Boosting is a hit or a miss sometimes on a battery reset I'm good for 20 miles others it's as soon as I test drive.

ive been told it maybe a exhaust actuator ,  but where is this routed to somewhere in the mid of exhaust ?. we have stock exhaust , but cant see how it works , how to it moved/actioned?. accelerator pedal?

We have spotted this in the rear left , and we are stumped what this cable contraption does .. it doesnt appear to be linked to the boot latch ..  We are looking at the cable thing