Ok so I'm looking at this Integra with an LS VTEC swap. B18A bottom end and GSR top end. Built properly by the shop that is selling it. These guys are fairly reputable, they do most of the builds that drive around my area, so I have a little bit of faith in them. They just got the head back from the machine shop the other day. So they just got it all put together like a day ago. Now I went to test drive it today, and bluish or black smoke comes out the back (I'm not 100% sure but I think it was blue(what does blue smoke mean VS black smoke?)). Like we're talking huge plume of smoke. That ain't normal. They said they're experimenting with ECUs right now, and supposedly the stock ECU was in it. Now I'm not completely sure, but I don't think you would run a stock ECU in an LS VTEC? Maybe they meant it was the stock ECU but they had modified it in some way. Is said smoke caused by the ECU? Or is it from something more major? Keep in mind I doubt there is more than 200 miles on the build yet. Could the plugs have been fouled? I had called them like 30 minutes before hand and it was idling when I got there. The business is located in a downtown type area, so I didn't really want to get on it too hard, plus with all the smoke coming out the back it didn't seem like a good idea. The smoke only came out during starting from a stop and accelerating in more of an aggressive fashion. Once just driving down the road it seemed to go away for the most part. Oh and they also said that the last time they drove it, there wasn't any smoke, so go figure. So if anyone has any ideas I would appreciate it. All your worst case scenarios and best case scenarios. I'm interested in the car, it's a 96' Integra GSR body, with brown leather in fairly good condition and brand new wheels and tires(not sure as to the make). They're asking 6k supposedly they're giving me a good deal, but you know how that whole make you feel like you're more important thing goes.