How to Test Your Car's Engine MAP Sensor

The car's Engine MAP sensor measures Barometric Pressure and Intake Manifold Vacuum to define the amount of fuel delivered to the engine.
Initially, when the engine is off, the MAP sensor measures the barometric pressure and thus tells the car's ECU how much gasoline to deliver.
The MAP sensor is fed with +5 VDC, and depending on the Local Pressure as a function of the height above sea level, it delivers a voltage that controls the amount of fuel suitable for engine ignition.
When the engine is idling the MAP sensor voltage is around 1 VDC and increases as the engine revs so that at full throttle the MAP sensor outputs around +4 VDC.
If the MAP sensor voltage is low at all times, regardless of acceleration then the engine mixture is lean and we have a loss of engine power.
If the MAP signal is high, say 4 VDC to 5 VDC, and does not change with acceleration then the portion of gasoline is higher than necessary in the engine, producing a RICH mixture and the engine is HIGH GAS.
In these two cases, the MAP sensor must be replaced because it cannot be repaired.
Before the change, the wiring must be verified in optimal condition and connectors in place and firmly connected.