I'll start from the begining. In the Haynes manual I noticed That they made a corsa without a cat.( engin no.12 NZ ) and I wanted to fit that down pipe to my SRI. BUT everyone denise its existance, all the locle tyre and exhaust places and there supplyers. Eaven Vauxhall told me they never made one untill I made them check on there computer. But now they say it could be months untill they can get me one, and it will be expencive. But I just thort that it might be the same as a nova down pipe, so I looked at my Nova Haynes and my Corsa Haynes and they look the same but the one with the cat is slitely shorter so I'll have to cut it down a bit.