What is Mass Air Flow (MAF) vs. Manifold Absolute Pressure (MAP)?

The Mass Aif Flow (MAF) sensor is device that detects the flow of air going into the engine. In the sensor there is a wire called a hot wire anemometer that the computer puts power through. As the air passes over the wire, it makes a cooling effect, and the computer will alter the resistance of wire. This reading, along with other sensor readings, is then used to determine and set the correct air/fuel ratio, fuel flow, and timing for the engine. This method of airflow measurement allows the car's computer to more easily adapt to modifications like freer flowing intake and exhaust systems. The downside is the MAF's screen and wires impeed airflow slightly. But read further on for possible modifications. The Manifold Absolute Pressure (MAP) sensor is a device which monitors manifold vacuum. It's sometimes referred to as speed density. It is connected to a vacuum nipple on the throttle body and electrically to the engine controller. The sensor transmits information on manifold vacuum ...  more