hello steve its very likely the coil at fault. You may also have a faulty injector compare resistances, but definitely replace coil if its a sagem unit. new one will be a different make. I had one last year with this very problem fault codes flying left right and centre did one injector first cause it was out of spec resistance wise but had to replace coil as well after this the car ran perfect but mil kept coming on when thrashed . New peugeot plugs (bosch) cured this even though new ngk,s were fitted hth Jez