Got a 2 inch on my 4AGE, That is plenty big enough, The 4 cyl engine doesnt put out that much air! anything bigger and you will start to lose to much bottom end. I got Straight thru with a resonator. The dick how did the exhaust put the resonator right up the front behind the cat, so it does nothing for the noise.
Sounds great but drones like hell at 100kmh.
Get a Hi-flow cat, that will make a much bigger difference than 3 inch for the 2 ft of pipe from the engine to the cat.