I don't think we are talking about the same thing. What I'm talking about is the Y-Pipe that comes out of the Intercooler under the supercharger and feeds the intake manifolds. This isn't the one that feeds fresh air to the Throttle body(part # 12 in the diagram). This Y-Pipe is pressurized after the intercooler. If you look down the back of the engine between the fire wall and engine, you will see it. It has some sort of temp or boost sensor in the valley of the V. Those photes from slk32.com kinda show it. Does anyone know Benz calls it or what the part number is? I've heard through the grape vine that is only about $100 from the dealer.