I picked up a CPO 2014 535d with about 8,200 miles and the service engine light came on within a few hundred miles. Went off for a while, then back on. Dealer service states "FOUND FAULT FOR NOX SENSOR. PERFORMED SIB 13 03 14. PROGRAMMED COMPLETE VEHICLE AS CONTAINED IN SIB". Less than 100 miles and the service light is back on. I assume it's the NOX sensor again, but can't get in for service till next week. No noticeable change in performance, seems to run fine. Anyone know the details for SIB 13 03 14? Any special advice when I take it back in to service?