Originally Posted by alexmtl_135i
I hope it's not the HPFP.. I have ruff cold starts, I need to let the car idle for like 5-10s when it's been parked outside in the cold, otherwise it would stall.
Is your car a DCT ? Many DCT trans cars have a rough cold start idle. I think BMW has a fix with a SW(software) update.
Do you have your JB set to "auto clear" the codes? You might be throwing a code(s) but the JB could be clearing them for you. I would take or turn off the JB and see how the car runs. Don't take any chances when you take your car in for service. Also when you have the JB in any of its maps(other than map 0) the OBD-II port will not work. So your dealer will know somethings up.