After looking for a front pipe for my van (none cat), my internet searching seemed to throw up that all or most Ducato based motorhomes have a none cat exhaust. But if you put your reg into GSF etc it comes up with a cat pipe. I got one already so not asking what I need, but I'm curious why they are changed to none cat? Is it all motorhomes? Does this have any any effect in any way such as emission zones in that there London? I realise this is a bit of a tech question and a bit chatty, so I plumped for here.