It could of course be doing what it is supposed to do and tell you there is a polution system problem like the cat is blocked or failing.It would of couse be more helpful if you said whether it was a diesel or petrol I assume its a petrol because diesels have a cam belt .

I am having the same problem with my Peugeot 207 Elle cc - Depollution System Faulty. Ive only done 12,000 miles and after reading some of the reviews on the internet it appears to be a common fault. Makes you wonder if the cars should have been recalled! Have you managed to get the problem sorted.

Have you seen a brown fluid on floor in front of O/S/Rear wheel ? there is a container with additive in it. If this is empty you will get a fault light coming on. Think that you need to take it to Agent to have it re-filled though.