If the MAP sensor detects unexpected conditions, a few things happen. The engine's computer will trigger the check engine light, and the on-board diagnostic (OBD) trouble codes will reflect the air pressure conditions in the engine intake manifold. Also, depending on what pressure reading is present, the engine may compensate for these conditions, causing the engine to burn excessive amounts of fuel, sending black smoke from the exhaust pipe. In this case, the OBD trouble codes would also reference faults recognized by the exhaust oxygen sensors. The engine may also have issue with idling roughly, failing to start, stalling, hesitation, power loss, misfires, and fuel consumption.
»MORE: How to tell if you have a bad MAP sensor