ok, so my r32 gtr has blown black smoke pretty much since i've owned it. its only visible when it gets up past around 5k revs, but even if i don't do that and just drive sedately, by the end of the week that back of the car is pretty black. obviously the first thought is that its running rich and so far, its had a tune with a pfc, and afr is at a very lean 12.5 and had injectors checked and cleaned and its still blowing smoke. any ideas anyone?
also, i'm noticing a massive drop in mileage. i used to get 450k's from a tank and now i'm getting about 380 but that's only recent. its always blown smoke though so i don't think the two are related. cheers guys, any ideas would be handy!