Ok.. so clean plug, and the 2 wires on the coil pack... might as well do a compression test while I have plug out..
Would a fouled plug / failed spark give incomplete combustion?
Would it sound different if not firing properly??
ECU had already been remapped, although it was on a 3 into 1 straight through with pod filters.. done the 12 minute tune, but will get it on a dyno as soon as I can, but here in spain they are few and far between