If you're dead-set on a CAI with no tune, there is a brand or 2 out there (can't recall what names) that have an insert that will restrict the airflow to prevent throwing a lean code. If you ever DO decide on a tune, the insert can be removed to allow you to get something out of the mod.

Personally, I didn't notice any more sound after installing my CAI & tune but then again, my Stingers were already installed.

 

Airaid is one of them. I can't remember the other one.

 

I ran a K&N CAI for a couple of years. At first when I got it, I did not have a tune for it and had no issues. It didnt add much power. But then getting a tune for it, it really brought out a nice power increase.

And even if you don't want a tune right now, you can always get one later. But you will get the most out of any CAI when you get a tune, too.

 

I have an AirRiad and it works well without a Tune.

 

I've had my BBK CAI on my 2009 Mustang 4.0 for about 6 weeks. Really happy with it. No tune, and still running 87 octane. I just disconnected the negative terminal of the battery and let the computer reset itself for the increased airflow. Really made a big difference for me (only previous performance mod was catback true duals).
I'll probably get a tuner at some point, but my 2009 sure did great with the BBK CAI. VERY noticable power improvement, and improved mileage, too. I get better mileage around town now even punching it more. Better freeway MPG, too.

 

I made my own setup using spectre stuff and it works and sounds great i have seen gas mileage gains also

 

Sorry to say if you do this (by a CAI w/o a tune) you are simply wasting your money. Either save up mod somewhere else, cause yes there are a few that make claims but in reality if you are bringing in enough air to make a true difference in power and preformance then you need to be tuned.