BMW MAP Manifold Absolute Pressure Sensor for M57N - Pierburg 136177871421 x Pierburg intake manifold pressure sensor Pierburg PN 7. 18222. 45. 0 OE PN 13617787142 A turbocharger boost solenoid is an component of a turbocharged engine, responsible for regulating the pressure of air entering the engine. The solenoid works by controlling the flow of exhaust gases to the turbocharger, thus controlling the amount of boost pressure produced. This part type is typically made of durable materials, such as metal or high grade