Yes you can. No point in doing it to think you'll get any more power. You won't get much out of the 1.2 16v. They all seem to be producing 80-84 bhp from the factory rather than the 74bhp.
I just put a pod filter on mine and left the exhaust as it is. I think I've got a video of one of the guys on here with a 2.25 inch straight pipe from the cat. It sounded brutal. But way too much for day to day driving. I'll try and find the video
EDIT : [youtube]wRooXImfgMI[/youtube]