It looks like we missed each other. Without knowing the exact vehicle it is hard to be as specific wit regard to the fault and its cause. As you mentioned it is related to a MAP sensor (technically an MDP sensor Mitsubishi uses on most models, but basically the same thing).
If you have not replaced the sensor... the vast majority of the time the code will be indicating that the sensor is failed and replacement is in order. The location of the sensor of course varies by model but is always mounted on the intake manifold, held on with two bolts, with a three wire connector. I normally recommend sticking with genuine Mitsubishi sensors, though I have seen aftermarket MDP sensors work out OK, they certainly are not as consistently defective like some of the other offerings.
If you have already replaced the sensor and you know for certain the sensor is good, then you will want to check your voltages at the sensor. With the sensor unplugged, pin 3 should have 5V with the key on. If it does not, check your wiring for damage and if all is intact, the ecu is suspect.
If you have good 5V, then plug the sensor back in and back probe pin 1 and you should see between 3-4 volts depending on your elevation. If you see outside that range but still between 1-5V, suspect the new sensor is bad. If you see 0V, check pin 2 for good ground.
If you see proper voltage, unplug the sensor again and check for voltage on pin 1 or pin 2, if you have any voltage there is wiring damage causing bleed over most likely, ecu failure second likely.
Realistically... it is very rare to see anything but the sensor fail when this codes comes up, provided there are no special circumstances like recent repairs, modification or damage that could have resulted in a wiring problem etc.