My 3 Series had its MOT today and showed a problem with the emissions test. 1st fast idle test it failed with twice the limit. The car display showed engine managment system in "limp home" mode. So they did an immediate 2nd fast idle test and it came in with less than the limit and it passed.

They told me this error message would remain on the computer in the car and would be seen and checked at the next service. I had had a full service last week. So I went to the dealer. The receptionist was no help and booked it in or a diagnostic check for a week's time.

Do I need to have this check, or can I ignore it? No problems are showing on the panel.