Are you sure it said "Duplication"?
I would suggest it actually said "Depollution"
https://howtomendit.com/answers.php?id=184371
https://www.ecutesting.com/common-faults/peugeot/peugeot-207-ecu-common-anti-pollution-fault/
https://www.honestjohn.co.uk/forum/post/index.htm?t=110253
fhstr, February 2020