When you cleared the memory , you put the ECU back to normal. You assumed the MAA caused the adaptation numbers to trip the code.
Now , with a new AMM, the adaptation has gotten out of limit again.
Did you get a bad AMM, I doubt it.
More probable that your original condition was caused by a vac leak or a bad fuel pressure regulator.
That is why it is always recommended to check those first , before jumping to the AMM.
The reason Techs go with the AMM test , is b/c they have one to use as a test tool , saving time without spending $$ on a part. They can leave the bad adaptation memory , do a quick AMM swap, drive around the block a couple of times and watch for the adaptation to get back in line. [ confirming bad AMM]
But for DIYers, I always recommend [and so does AllData ] looking for vac and doing a fuel pressure test.
If you go back a couple of post that you posted on, read the one by Steve B. and MB Stars... they explain it to the T...
The reason your car ran better is b/c you cleared the memory back to normal. It was not the results of the new meter, but rather the proper/ short lived ECU mapping. Which has now gotten back out of limits.
As I said , you may have gotten a BAD meter, but I doubt it......