Hey ya'll i got a 2004 Frontier 3.3 Crew cab which im pretty sure is the same engine as the X. Im looking at upgrading the intake, not a cold air but just buying one of those adapters that allows u to eliminate the factory air box and replace it with a performance filter. it allows u to use the factory MAF and everything just allows u to replace the box with a performance filter. i would appreciate some advice guys. the frontier forum is dead as all get out.

OK, what do you want to know? They all cost a couple hundred bucks or more, and they all offer marginal improvement in performance. K&N, AEM, and Nismo all offer open-element intake kits as you describe. The ONLY one out there that actually offers a "cold" air intake is the Volant kit which has a replacement air box that pulls air from the fender like the original instead of hot air from the engine bay. I know the K&N FIPK has a shield of sorts but it's not as effective as it should be.

Plus you'll get a "throatier" sound.

hey thanks man you sound like u know a lot about all this stuff lol.
http://cgi.ebay.com/ebaymotors/99-04-00-02-03-01-Xterra-Frontier-Air-Filter-Adapter_W0QQitemZ320212493005QQcmdZViewItem?hash=i tem320212493005
that is the thing im talking about, all it does is let u put a filter on it. just wondering if that would at least work a little. and if there are any kind of gas improvements that go with upgrading the filter.

Not enough for you to ever recoup the money you shell out for the system. I have on, don't get me wrong.

see thats y i was looking at this adaper, costs like 10 bux with shipping. keep the entire assembly, except u replace the factory air box with a performance filter, the tubes, MAF and all that stays put, so its jsut the filter being replaced. and u can make a heat shield and boom, instant FIPK lol. but thats bootlegged, but i would assume it would work at least a little. but the only thing is that the vacuum hose cant be reused and i dont know how important that thing is.