As said it runs for no more than 90 seconds on a cold start to warm the cat up quicker. After that it does nothing! You can remove it but you have to fit a resistor somewhere in the wiring to fool the ECU in thinking it's still there. The is a link on uk-mkivs somewhere I think
That is rubbish mate, have you ever done it or are you just passing on information you have read on forums?
I removed mine and the car was hesitating on boost and just generally not as fast or smooth. If you remove it you need to get it mapped out as it clearly does something. If you are not prepared to get it mapped out then dont do it. Mine was bad enough that i had to go through the effort of putting it all back on.
On my new engine i am not going to have one as they are prety pointless but they DO need to be mapped out!