Hello All, I just bought a second hand 2003 525 and SESL just came on. I did just fill up last night and I am going to check and make sure I put the gas cap on correctly. If that does not correct the problem what should I look at next. Could it be that I need to change the oil? The car has 91k mike the sticker has 94K for the next oil change. The first owner used synthetic oil. Could it some one forgot to reset the when the oil was changed. I have a OBD2 reader for my F150 truck I understand that I should get a new OBD2 reader designed for BMW. Does any one have a recommendation?