I am getting the Check Engine/Service Engine soon warning. When I run diag, it says it is an emissions-fault. Is this anything I should worry about, or just ignore it? 2002 745Li with 51K miles.

I recently moved and closest dealer is 1.5 hours away so it is a pain to take the car in.

Note: the warning came on the day after I got back from dealer for an oil change. Coincidence or is it possible they forgot to do something?

TIA