Petrol and diesel exhaust interchangeability?

[clarkey1984]

Hi all, despite only having a new centre section about a year ago, my sub standard welding means it's not exactly neat and has some scabby looking rusty bits on, plus the odd pin hole blow, and also my rear section where its joined to the custom rear box I made is absolutely shot where the flange joint is, I need to change the lot out really, and then get someone who actually knows how to weld to a decent standard to do the same box removal that I have done only properly, however, I'd like a slightly larger bore system ideally, and if my memory serves correctly diesel exhausts are usually of a larger size than a petrol one.

I have looked at various pictures online and it all looks identical in terms of how it all goes together on my petrol one, and the car is obviously the same shape etc, and in light of me only needing the cat back section, I just wondered if with a bit of jiggery pokery I could just get a 1.9d system, the boxes are irrelevant as I'll be running my single rear silencer only as it is now, id just like the larger bore for better flow and no blows, anyone know if this would work?

Thanks in advance

EDIT: actually it looks like the diesel middle section would bolt on where my existing cat would bolt to the down pipe, which is actually a double win because I was toying with the idea of getting a high flow 200 cell cat anyway, provided this can be done I'm well up for it!