The OEM cat is part of the manifold so to refit is a pain and nonsense imho! The sports cat will do the job and won't effect performance at all!I think he was just talking about the sports cat.
That didn't work for me as the light kept coming on with the extender pipe I bought and had fitted. So I went with the sports cat and all was well and no more light coming on when giving it some!As I said to you in another post the port where the second sensor goes in, get a short piece welded on to move the sensor away then reset the light. it works trust me as I have it done.
After I had mine fitted I took it to my local garage that does my MOT and put it on the emissions test and it sailed through hence my recommending it. Car is currently off the road so once it's finished it will be getting it's MOT and I don't doubt it will pass with the sports cat fitted.Mine worked so must be slightly longer.
I replace all mine every year but have thought about sports cat has yours gone through not yet with it on.
I bought mine via ebay was a 2.25" magnaflow sports cat 200 cell, I'm sure Nige has a more upto date link then I have m8.Rich can you send me the make and a web link if bought online. As I'm going to get one fitted, so I don't have to do the change every year