Factory cats/exhaust manifolds/catback

[slyscot]

What's up. I'm new to this and want to learn a few trick of the trade when it comes to my 05 G35 coupe 6MT. I have done some previous seraches on where to get started as far as increase in hp/acc, but my question is are the factory cats and exhaust mans sufficient when adding plenum spacers, intake with z-tube and a cat back exhaust? are they worth the time,money and hassle of changing out? Also is magnaflow a decent catback exhaust? Sounds good but not sure.Any advice would be greatly appreciated.

[audtatious]

I believe the plenum space, followed by high-flow cats, can give you the most bang for the buck. The intake and exhaust is not that restrictive but can free up some ponies.

I was considering a Magnaflow at one point and they seem to sound good. Price is good. Not sure about longevity though.