I am brand new to ODYCLUB but already have found many helpful tips and would like to give back with a tip of my own that I hope is helpful.
I have a 1998 Odyssey LX that I have owned for a little over a year and have recently begun to "mod". Like most DIY tuners I started with the basics. I searched for a while looking for a better intake set up, because the OEM intake box and piping is incredibly restrictive. I soon realized that the suppliers for after market parts for a 1st Gen Odyssey are limited. However, after market parts for Honda Preludes are in great supply. This is good news because the F23 in the Odyssey is similar to the H23 in the Prelude.
Taking that knowledge I have found many many cold air intake setups for the Prelude that fit an Odyssey. Now obviously you can spend big $$$ on a big name brand setups. But I'm a college student and prefer to do things a little cheaper.
The setup I put together is not a kit. Here is what I did.
1. Ebay is your friend here. I found a multitude of those "backwards 3" shaped short ram aluminum pipes for next to nothing from smaller name tuner companies. I scored mine for under $10.
2. Measure the pipe opening diameter and your throttle body opening diameter.
3. Go to your local auto parts store and pick up a rubber coupler and two hose clamps to secure the intake pipe to your throttle body. A small rubber hose that is used to vent your valve cover (or use the stock on that's already there). And medium sized cone filter. I picked all that up for around $30.
4. That cone filter should already come with a rubber coupler and hose clamp, so fit it to the far end of the pipe and it should sit happily behind the battery box, once you have removed all the stock intake piping.
So less than $50 and you have a performance intake, giving you better fuel economy (though honestly I like the deeper throatier intake sound that was achieved so now I have a bit of a heavier foot and my mpg has gone down lol

) and better power.
Obviously this isn't the only way. This is just what I chose. Hopefully this helps to get those mechanical juices flowing and think outside the box, instead of getting suckered into paying hundreds of dollars for some big name parts company to put a nice little kit together for you.