Concern- smoke coming out of back exhaust at start up Cause — TAYLOR BMW (dealership) — possible needs updated oil line, turbo may be leaking internally Correction- dealership pulled faults to see if cat efficiency faults were present, saw none. Did verify smoke on startup. Doesn’t look like the turbo oil feed line has been changed (updated with check valve). There is some oil encrusted on the body of turbo. Would replace all lines since turbo removal is required for any of them; however once cat is off and if the chamber inside is wet with oil, at that point it would need a turbo as well as the lines. The above is the written diagnosis from dealership and I was quoted a price ranging from $2600- 4600- In 2016, NHTSA issued a notice for certain models/ years regarding the turbocharger feed lines (extending warranty for that part to 10 years / 120k miles). My 2016 was CPO and has only 84k (all maintenance performed by BMW) and I believe it should fall under eligible vehicles. I have reached out to BMW customer care, spoken with a case manager , all to no avail.