hi! new guy , but probably old problem. got a 2003 , 307 2litre petrol with "depollution system faulty" message on screen display. car running like a pig with flu.had diagnostic , and been told its a crank sensor fault. would that be crankshaft position sensor? or is there another sensor on the crankshaft as well? the mechanic cant seem to give me a straight answer ,(to be honest , not sure he knows himself) and after reading a lot of comments / problems with peugeots of this type , hoping somebody can point me in the right direction . heres hopin!