how much would cold air intake cost??
and how much hp would it add to my 03 honda accord ex 4cyliner auto?

Check eBay
5-8 hp

my intake was like $40 shipped off ebay, but make sure you replace the ebay filter with either an AEM dryflow($45 at Advanced Auto Parts, which I bought) or a K&N filter(~~you have to oil this one). so altogether I paid about $90 for the intake and then new filter. it will add most likely5-10 hp, mayb a lil more if your lucky lol

CAI: 5-8. Closer to the 5 if you have a 4 cylinder auto.

The 10 estimate is for if you have a 6 cylinder...they benefit more from breathing better.

Nonetheless, get the CAI...it's the first step and arguably easiest step to modding your ride.

I second the ebay idea, however, i found this site that has specials on random parts, i forget what the site was but they had AEM cai's for integras and civics for about $120 or $130! But ebay is cheaper and they work just as good but you are not going to get as good of quality as you would with AEM or something else

u dont really need and air intake for more power u can just get anair filer and slam it on if it fix ur car but u have more power if u got an cold air intake but it not good for rain

correct me if i'm wrong but the aluminum piping stays cooler, or something like that compared to the regular plastic piping from the stock one. Plus, the intakes look cooler, and they do add more power and they are smoother. As far as the water getting in the cai, it's not going to do that much unless you drive into a HUGE puddle, and i mean huge, and submerse the entire thing. Also, you can get a bypass valve for your cai, that way you don't have to worry about your engine ever locking up. There are many people on here that do not have bypass valves with their cai's and they have been fine, but the bypass valve just gives you added insurance.

^ Correct

You need to fully submerge your cone filter for any chance of hydrolock...I dunno about you, but that's a good 3-4" off the ground. Unless there's a friggin tsunami, you should be fine. The worst rainstorms only get 2" rain here and I live next to Inner Harbor, baltimore.

Eh....I wouldnt want the filter getting wet at all. Mine has, so I filled all the gaps I could find such as the headlights w/ clear RTV. Here is why I think any amount of water is bad....

When you remvoe your OEM intake, you'll notice a chamber that is about 1 foot away from the intake manifold and the chamber goes down into another horizontal tube that is close off. The point for that is to catch any moisutre or water in the intake piping. I dont think they would waster their time molding that into the intake piping for nothing. Just my opinion

only if they could do that with alumnium....

Yeah!
When I get my projectors, im planning on surrounding them with black RTV to seal any gaps that would allow water in to the bay and get in the intake.

cant you just get an air bypass valve? that would solve your problems with a cai

It robs some performance and some CAI units are not compatible with it...just use common sense people! Not that difficult! You wouldn't want to ford rivers with an Accord anyways....or would you?