Hi, my 1.8t was having erratic boost issues since i got it- sometimes it would pin you to the seat and other times it felt flat as. The car came to me with superchip eprom fitted (documented and stamped ecu cover) In a bid to cure this i have changed dv to forge splitter, n75 to the J version, boost hoses all replaced, TIP replaced with silicone, but still the problem continues. Changed FPR vacum hose, changed vavum hose from DV to inlet. On the vdo boost gauge it under load will bosst to 0,5 bar maximum then drop back instantly When i rev it and jump off throttle the revs hunt low for maybe 5 seconds then stabilize at 850rpm as expected. Read as much as possible and can't work it out- have swapped the maf to another one and that was same?? HELP!