muzzler

Hi guys been a while since I was on forums....now have time to play again with the scoob, my 06 WRX (mapped to 290 by JGM) now has a hesitation when under full boost in 4 and 5 gears at about 3500 to 4500 revs and then it goes. Worst was when on my way down to Le Mans and the engine light intermittently came on with each hesitation......no fault codes stored.

Any ideas or how to diagnose what the issue is?

Thanks