Some vehicles use a mass air flow sensor instead of a MAP sensor to measure the amount of air going to the intake manifold.

The other popular type of EFI system, Speed Density, features a Manifold Absolute Pressure (MAP) sensor as its frontline warrior. A Mass Air Flow sensor is usually mounted near the air filter box ...

He decided to replace this with a modern mass air flow (MAF) sensor instead ... To figure out how to map the MAF’s output to match the AFM, [Rob] built a rig to blow air through both devices ...