there should be a serial number on teh sticker on teh chip, stu can match that to his records and tellu exactly what the spec of th chip is,

u cant really say all atg 3 are 22 psi say,,, some are 22, some are 25, mine is 29 peak and then backs off to a held 25, but that is cos the chip is mapped for that and it has had the full setup and been checked through the boost and revs on teh road by stu to make sure its all good,

i'd say for the sake of 100 quid to have stu give it the once over, its well worht it as any problems that u may not even be aware of may become aparent that could cost big money if not tended to early before it goes bang