yes as nick as stated all a31/c33 ecu's are poo for tunning/power , they basicly have a heart beat of lean AFR's which do them no good when its time to tune/ make more power, i even noticed nearly all hunting issues gone and a smoother run once i ran a r32 ecu in, credits to trent at checkered tunning for giving me the heads up
note, pretty sure i stated the same thing in this very thread, fail! for not listening to my online gospel preaching