ok here is the story wife has a bad habit of running the 318 on reserve petrol supply! i told her not too, and noticed on startup while still in park the car seems to rough idle, the same alos when shifting into D or R, then after a few minutes it is fine, then fine in D at lights etc...so maybe a good or bad idea I dump some stp total fuel system cleaner in the gas tank and the roughness has gone, so maybe fuel impurities caused the emission level issue on dash?that is why it would be great if someone knew how to reset it easily?