Citroen do not manufacture the CAT, they will be supplied to them via a manufacturer. Quality control measures will be in place at Citroen to assure that the product they are receiving is fit for purpose and to the correct tollerances and specification. Through testing it has been identified that they are not to spec hence the letter landing on the door mat.KoolKat1 said:I also received a letter stating the catalytic converter MAY not conform to the technical specification of my car!!!!!! The word MAY changes the whole context of the sentence!!! CITROEN must know if the parts they use conform or not BEFORE the model goes into production!!!!I .