Hi all. I have asked this question before, but thought I would give it another try for fresh ideas. Car was fine a month ago, boosting and holding at 14-15 PSI. Now if I am in a low gear and hit the throttle the car surges and the boost gauge flutters. Seems to go ok, but does not have the kick it used to have. I was wondering if I ought to try a different N75 valve, maybe the J? I did phone AMD where I got the remap done, but they said the standard N75 should be fine. Boost holds at about 11-12 PSI which seems a bit low. Also 3-4 months ago I had a full Milltek fitted with high flow cat where they removed the air box to fit it. ........wondered if there was anything they could have moved or caused a problem with when they did this. [img]/ubbthreads/images/graemlins/noidea.gif[/img]