I was thinking of getting a Pop Charger instead of the CAS since the Pop charger costs $165 less. What are the pros and cons between the two?

Well Pro's of the JWT Pop Charger is that it's cheap, and frankly it looks cheap. All it does is replace the factory airbox with a cone filter. The CAI's (which most for our vehicle are true short ram style, not CAI's) are quite a bit more since they come with intake tubing to replace factory tubing. Some, like the Volant, come with a real sexy filter box that trys to protect the filter from heat soak from your engine. Both designs are less protective than your factory setup as far as water is concerned. Unless you just have to see something different under your hood I would go with the K&N OEM replacement filter. The performance difference is little or nothing from any intake you might install.

Thanks, but how would the OEM replacement filter be similar to the Pop Charger in that there would be little difference between the two? I thought the concept behind the intake filter is to get greater air mixture.

Well you have to realize putting an intake on to begin with will give little or no performance increase(though it may improve mileage and throttle response). Having said that understand the Pop Filter is just pulling hot air from under the hood. With the factory intake in place your at least getting fresh air to your engine, not hot ass engine air. Thats why even with increased air volume from a "cone" type filter your sucking hot air, which IMHO negates the performance benefits. Not that us Xterra guys don't know a thing or two about intakes here you may try looking in any Honda-Acura forum, lots and lots of intake talk around there.

Again thanks. So I guess the CAI System would be best since a box is usually provided with them. Hence blocking out the hot air but allowing mass quantities of cold air to flow through. Bye bye Pop Charger and hello sweet CAI!