I agree , in the case with craigs friend it has had a new bigger intercooler fitted and that could possibily be at fault , or its related pipework.
But considering most of the cars out there that have this
problem only have the
problem after a remap alone and not only when fitted with a bigger intercooler.
It leaves the software/remap at fault since most cars were 100% perfect running as standard on standard software.
What im trying to say is, if the car is as above. 100% b4 remap.
By altering the remap/tuned software using DAMOS to find the deviation value this can iliminate the fault ever repeating its self.
something most tuners dont use or are intrested in using.