Had that over a year ago... did an oil and filter change, and within a week, the fault had corrected itself. It's come up again though, and "anti pollution" fault has been illuminated now for over a month, though it runs fine. Intend to flush engine, and do another oil / filter change (long over due...) to see if it does the trick again. Not really bothered though, as from what I read last year, it's a common problem, and often just dirt on some kind of sensor.
Paul, January 2011