Difference in MAF scaling steady-state

Hello,

After learning the practical reflashing course and following the Ecuflash videos, i started gathering data for my MAF rescaling. However when i do my 2000rpm run (lower then my Engine Load Compensation peak) i have -2% total trim. But when i do my 4000rpm run my total trim is +5%. When i do my WOT run it's around -1% until the end of the run it starts creeping up till -3.5%. Only thing i can think of is: i did my 4000rpm run after my WOT run and thus my ECU was reset. Do i need to drive more before doing another steady-state run?

Thanks,

Tom Neuteleers