I've been searching not only on this forum but other tdi ones but I still haven't found the answer, I'm thinking of DIY mufflerectomy on my 03 plate pd130 tdi ibiza. But I don't know the size of the pipe I'll need to get to take the place of the cat and middle silencer etc.. I can measure the length easily but I don't know the diameter of the middle. So does anyone know the size I'll need to get so it'll be a straight swap with the help of some exhaust clamps and even better where abouts I could buy the pipe from?