i have a k&n fipk intake and it does help
What gears/tires do you have?
Stock exhaust is pretty shoddy too, if you can, dump the cat, if not, keep it, and run a straight pipe, or a high flow muffler back from it. Headers would really help too, but those are REALLY pricey for the 3.0 from what I've seen. The collector is a terrible design, creates a lot of heat and turbulence where the exhaust comes together.
