hi all over the last week my car has developed a misfire under load. it started every now and then to now all the time and the orange management light is on and sometimes flashes. my garage cant get to look at it till Wednesday next week, any ideas what it will most likely be? ie common fault, and i am worried about using it in case i am causing any damage, BTW it is serviced every 10,000 ish and only done about 3000 miles since the last service.