Need a little more info here to help out more. Was it a V6 to V8 swap or replacement for blown motor? Is the computer the same one from the donor motor, original to the car, or a separate one, is it factory tuned or tuned with HPtuners/LS1edit etc? Same with the wiring harness. Is it a patched harness or donor harness? Sounds like the signal from the MAF is wrong with what the computer wants to read but not enough to trigger a SES code. Does it trip SES when unplugging the MAF? What did the MAF come out of, aftermarket or another vehicle. Same with the previous ones were they junkyard pulls or new ones? Need this so I can try to see where ya need to go. Push comes to shove you can always SD tune it if it runs fine without the MAF but better to solve the problem first then decide on what tune to run.
2000 Red 1SC Z28 A4 - dead for now
2005 Black GTO M6 6.0 - Split daily driver
1987 Silver Fiero GT - Split daily driver