I have a 1.8L, but I am 99% sure that the exhaust diameter is the same for both models. I did a 2.5" cat-back, with a magnaflow high flow cat and removed the resonator, I also put on a 2.5" inlet, 4.5" outlet ractive ricer muffler hehe. I lost some low end power, but picked up a little top end. I would probably get a 2.25" if I did it again, but it is up to you.
BTW my exaust does sound ricy when I first start it, but after it warms up, the exhaust sounds excellent, smooth and deep. It only has that raspy buzz for like 1-2 seconds right around 3000rpm. Overall, I am very pleased with it. Good luck.
