The manifold pressure (MAP) sensor for the E90, E92, and E93 M3 is one of the sensors used by the engine computer for setting fuel and timing tables. Therefore, it's integral to engine performance. The S65 V8 ECU relies on throttle position, camshaft position, air temp, and atmospheric pressure to set running conditions. This sensor measures atmospheric pressure inside the intake manifold. A fault in any one of these systems can affect engine performance and power output. On the E9X M3 the MAP sensor is located in the idle control valve ducts.
Generally, these sensors are very reliable. But if your M3 has misfires, rough running, loss of power, hesitation, or other running issues, and you have not already replaced the BMW fuel pressure sensor
, you can start looking at the rest of the engine management sensors.
BMW Fitments: 3 Series
E90 / E91 / E92 / E93 (06-13) > M3