I have the same problem with my 135i. I had catless downpipes catless midpipes muffler delete. I was thinking it happened after i went full straight pipe. I was thinking no restriction so smoke would go out of my exhaust, mine was crazy smoke like embarrasing! lol I put my stock downpipes back on and it stopped smoking. Looks like we both need catted downpipes now!
|'08 Jet Black 135i|CCW Classics 18x9et 28 18x10.5 et 44|Vis Carbon Fiber GTR Hood|Icarbon CSL trunk|Carbon Fiber Quad Diffuser| Custom Quad Straight pipe | DTM 1M Bumper With lip | VRSF 3INCH Catless|VRSF 7INCH FMIC| Alpine Hid Kit 6000k|JB4 ISO 5|N55 Midpipe|E85|