ive just fitted a -31 actuator as my standard one woz fucked n holding like 3 psi which was pants!
anyhow this -31 keeps peakin at like 10psi sumtimes abit more but only in like 4th n 5th on the motorway n i jus back off immediatly and it keeps hittin a flatspot but the thing is it didnt when i 1st put it on it was rapid! wen i first fitted this -31 it was well fast n ther woz no flatspot (yes i no i shud have had it setup, doin it this weekend at weston).
anyhow at the mo if i spool it up slowly n plant my foot it boosts n there isnt always a flatspot, but if i plant my foot sumtimes its like hitting a wall the flatspot is. is this the fuelcut in the ecu? or have i got a fooked tps sensor? i think i jus need less boost tbf until ive had it setup properly but i jus dont understand how it woz boosting really well n now its jus not

 

hitting boost limit on peak boost,

if your having it set upo, may aswell chip it at same time and go for 14 psi

 

Sounds like you need to chip it, as its hitting the boost limiter as what zippyobrien states

 

defo need a chip i had same prob