I have a question?
is it true that those famous chips that are beeing sold on e bay work??

Depends on what they're selling. The "G-Box" module seems to be pretty good, and the customer service is pretty good. They also stand behind their warranty and money-back offer (and also offer upgrades to new models that come out for existing customers). A buddy from work put one on his '04 Taco and swears by it. I haven't tried it personally on an X, but I imagine the performance would be about the same. Watch out for the ones that just sell a $0.19 resistor from Radio Shack that just fools your ECM. There are a few other threads under "Performance" on this topic...take a look.

If you buy a chip from ebay for 20 bucks you will be the laughing stock of the Xterra comunity. Hell even the mirage owners know its scam.

AAAMMMEEEENNN! Get an intake...at least there's some proof that they work. Not just some redneck selling Radio Shack parts...

uh, i just checked superchips site and they don't make one for nissan, AT ALL.

if they did, i would as i was extremly happy with the one i had for 3 years on my diesel superduty

thanks Guys I will not fall into scam