The Intake Air Temp Sensor (IAT) 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 does not use a traditional air flow meter (HFM). Instead it relies on throttle position, camshaft position, air temp, and atmospheric pressure to set running conditions. A fault in any one of these systems can affect engine performance and power output. On the E9X M3 the IAT is located at the front of the intake plenum.
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