You have to reset the PCM when it sets a code. If it set the code for the MAF then you fix the problem it will still show that code in its memory. You need to clear all codes, swap the MAF from the other car then start it up and see if the code comes back, if it does come back but its the opposite code of your original , that is pretty weird but you might have a wiring issue to the MAF from the PCM.
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