Originally Posted by asting
I too am/was hesitant about the noise changes to my vehicle. It's a 4 cylinder econobox, so it shouldn't sound like a monster. I just installed the K&N Air intake kit (got it for like $240 or so on Auto anything by asking if they could honor the 15% off new members), and that included the recharge kit.
It's not too much of a difference in sound level, only when you get on it. It does have a weird rumble around 1800-2000 rpm (probably due to resonant frequency lining up). Cruising and if you stay out of the throttle you can't tell the difference.
It definitely pulls a bit harder, and this intake has been dyno'd to show ~10hp increase by K&N and some owners have shown more than that.
As always, YMMV and it depends highly upon your specific engine.
The thread above has a bunch of different intakes, so you can see that the intake alone is definitely worth it if you want a few extra ponies.
I purchased but have yet to install my exhaust kit (will do so in the next few days). I've heard the magnaflow is the quietest of the exhausts, so that's what I went with. I'm hoping I don't have to add/swap out resonators, but I think it should be okay. I'll update if you'd like about sound level. I'm okay with it being grumbly and loud as long as it can be quiet when I need it to.
I too was a bit hesitant about installing the exhaust but after listening to a couple sound clips of the magnaflow, I was sold. It is not loud at all unless, like you said, you "get on it".