BCS - boost control solenoid aka the party pooper
Reply #32 –
The BCS is the black gizmo on the PS firewall near the strut tower. It easy to find, if you follow the vacuum lines from the turbo to the firewall. You actually don't need to know where it is, just disconnect the two lines from the turbo (at the compressor inlet), connect one piece of hose at those two points. The length of hose matters, so experiment. Make sure you have premium fuel in the tank and the knock sensor connected when testing. And have fun.