The IAT1 Intake Air Temperature sensor is often used to replace the stock IAT sensor when MAF (Mass Air Flow) kits are installed. On many air flow meter (AFM) cars, the IAT sensor is internal to the AFM. When the AFM is replaced by the MAF sensor, the stock IAT sensor is removed. The IAT1 replaces the stock IAT sensor and can improve cold start performance. It is generally installed in the stock air box in front of the air filter. The IAT1 comes with a connector and nut to hold it in place.