Hi just bought another focus st170 53 plate 103k very good condition but has eml light on but not affecting the car in anyway what so ever and passed the mot with it on but was on advisery that it was on ,Anyone have any ideas what it could be as the owner has said its something to do with a sliver box down next to manifold something about a connection has gone rusty but I don't know anything about these cars yet ,any help would be great as would like to get the light off lol