dont have citroen part number or fram number, for the air filter, but peugeot part number is 1444cp for the same engine.should be approx size of air filter box. on peugeots access is restricted. remove turbo pipe from turbo to air filter, (again!), 2 jubilee clips and clip off breather. unclip wire from air flow sensor, the air filter top comes off air filter box to allow access to filter. it has screws along front 2 or 3. might have to clamber on engine to see them. unscrew these they dont have to come out, just loosen all the way, and if your lucky the back will clip out of air box, lift forward and upwards. if not then they have put 2 or 3 screws at back of filter but im sure it just has 3 protusions which slot into air filter box.try not to pull whole airbox out, as its hard to get back in, and the rubber grommets it locates on fall down back of engine ,and it will cause bad vibrations inside car if these grommets fall out. nightmare eh?
me
July 2009