MAP sensor and its effect on fuel economy
The manifold absolute pressure sensor (MAP sensor) provides the vehicle’s ECU with information about the load of the engine. In other words, how hard the driver is pressing on the accelerator pedal. An engine works harder (more load) while going up a hill than going down.
The MAP sensor controllers make the vehicle think it is always driving down a hill, therefore requiring much less fuel.
They balance out all the signals of the fueling system, maintaining full engine performance and preventing the “check” engine light from illuminating.