Hi Mate, Brian at Exhaust Innovations changed the cat for me and it is a 100 cpi hi flow cat, the tune on the ZF has changed the way car drives (for the better). Clinton has only just started the ZF tunes as everyone has been waiting for the release. I am sure he would be keen to have a look now. As for petrol consumption, that is strange tah it has gone up. I changed from normal fuel to Ultimate and that alone dropped me from 21 to 19 per 100k. Since the tune it has levelled around mid 16's and that includes a night at willow bank, and yes I do drive it to enjoy the power. cheers