The other day I was driving my , the reduced engine power came on.

When a particular code is registered in the computer, a light may come on. But it only means that the system in whole, that the light is referring to, has a problem. There are a few different parts to each system, not only the sensor itself. As with an oxygen sensor code. This can be triggered by other things like a vacuum leak, poor fuel or even a bad or no connection. Not necessarily the O2 sensor itself. Because the MASS air flow sensor monitors just that, AIR, you may want to check for a dirty air filter &/or leaks between the sensor and the engine. The tubing / duct that the MASS Air flow sensor is mounted in MUST be sealed, so NO air leaks in. OTHER THAN the air coming through the sensor itself, NO air should be allowed. Also check the wiring to the sensor for bare wires , broken wires, or lose &/or bad connections at the plug. Also follow THAT lead to see if it has a secondary plug that may be bad.

Have a scanted performed, live data can be viewed to check various systems ... Code reader will not help as you now have a code for the MAF sensor for sure!... Guessing can get expensive and lead to false readings during a diagnostic test!

Clear code(s) , re-install original Mass Air Flow meter , will it run?