For what it's worth, here's my experience with cleaning the MAF after I got codes P1123 & P1125 last year :
http://986forum.com/forums/showthread.php?t=11810
P1123 Oxygen Sensing Adaptation Area 1 (Cylinders 1 - 3) - Lean Threshold
P1125 Oxygen Sensing Adaptation Area 1 (Cylinders 4 - 6) - Lean Threshold
P1128 Oxygen Sensing Adaptation Area 2 (Cylinders 1 - 3) - Rich Threshold
P1130 Oxygen Sensing Adaptation Area 2 (Cylinders 4 - 6) - Rich Threshold
Nick