yeah it does, IMO sounds a lil deeper and tinnier in a funny way, deffinately a nicer exhaust note.
Take dash top off, remove instrument panel, strip dowm and remove led.
Thats what I'm doing on mine have got more than one light on anyway.
Have engine management light, service light, esp light one and emission light so thats what i'm doing.
with the one i've got on me cup, i have the first lambda fitted into the pipe, than the second one is taped up (stilll connected to the loom) under the car. I have the hole in the decat plugged up
not come on for over a year
oh and because you've changed the seats that'll cause the light to be on also, are your std seat belt pretensioners still in??