I had Powerflow do me up a full s/s system man from the downpipe back, with only the cat left in, no other boxes...and its loouuuuddddd! i gave my gf's dad a sore head one night! mines a dual exit jobbie, not exactly jap but ahwell i was young and when its clean it looks pretty cool to me so i like it! as for gains, i know its made her breath a little easier but i cant honestly d say i felt much in the way of power, maybe one or two very small, young ponies, nothin noteworthy, wont lie to u like, it is only an n/a after all is my wee motor. as for the lamda thing...i know more Cantonese words (thanks to lessons from Shelly) than i do about that sorry. i suspect Joz will be able to help u out there. Phil.