since having my car remmaped its been playing up when accelarating in 5th or 6th gear the boost starts fluctuating i can hear the tune of the turbo changing as well it doesnt seem to be holding a constant boost i have tried unplugging the MAF but its still the same i have also checked around the tip pipe for splits or holes im starting to think its the n75 valve isthe n75valve the one with the 3 small pipes going into it located near the dump valve on the AUQ engine im looking into buying a new n75 to see if it will cure my problems wich would would be best n75 to get with my car been remmaped can i fit a standard one or is there an upgraded one for the remmaped engine any help will be much appreciated so far ive changed the coil packs and the spark plugs im at the end of my tether with this problem