if its a diesel most peugeot's have a extra tank hidden under car that has treatment for the exhaust/cat to work more cleaner.....if this treatment needs topping/or blockage etc it will bring up a picture of an exhaust on the dash stating antipollution fault....its a dealer fix proccess cause not many mechanics know what to do or even know its there.
the manual will tell you to drive at a certain speed to correct fault but if this doesnt work it will need attention a.s.a.p to prevent other damage
rob
October 2009