UKPassats

Hi all my 1999 B5 1.8t apu has started to hesitate around 3000 revs more so in 3rd 4th and 5th,it does stumble through then all is fine. Its been remapped by simon sponser from here a few years back and has been fine since then,up to a few weeks ago. Ive replaced plugs and oil still the same,stuck it on vcds lite and maf code po102 came up but that's coz I unplugged it which made no difference,its now plugged back in. Cleared code and no codes have come back. Coilpacks look ok but haven't tested them properly and cant hear any vac leaks but again haven't tested them as I haven't the equipment. Pcv hoses are all ok as well.
Any ideas chaps am I missing anything?
Cheers