I just changed (like yesterday) the air filter on my 2006 M6s and I'm noticing that the car idles below 750 rpm. There's a slight surge too. Could it be the engine reacitng to a better air intake, orcould Ihave donesomething while replacing the filter to cause this?

 

i'm having the same problem so i'm about see about the fuel pump or the filter.

 

It seems that it's now idling at normal speed (approx. 750 rpm) so maybe it was just getting readjusted to having a cleaner flow of air. How long has your car been doing this?