Catalytic Converters 2003/2004

[notworthy]

Hey guys I have a question that I need help with. I love cars, am mechanically minded but, don't know very much when it comes to performance etc.

I recently had a Gemballa exhaust installed on my 2003 2.7. In Australia we only have one set of cats after the back box connected to the 'U' bends (lucky us). My question is related to the catalytic converters for the 03/04 models, which I believe there was a change - is there a pipe diameter size difference between the 'S' and non-S models?
I ask as the 'U' pipes had to be modified (reduced) to sleeve together with the cat converters on my non-s model (2.7L).

Now, having said that and if it is the case that the size is different, am I better off getting 'S' model cats to fit to my car (and having new or reshaped 'U' bends back to the original size) so that the flow works better?

I am not looking to buy 200 cell cats at this stage plus the exhaust is pretty loud as it is!


A real technical insight into this and a knowledge of any changes in the 03/04 models would be great.

Thanks, I look forward to some feedback.