I figured this would be the best place to post this question, if not let me know. I found a company online called Tweaked Motorsports, www.horsepowerchip.com (http://www.horsepowerchip.com) that makes a performance chip that will work on the Xterra. They claim a 17-20hp increase but I seriously doubt it is that much. Does anybody know if this is worth getting or is this just some cheap resistor with a fancy sticker that won't do much except make my gas milage even worse? Any feedback would be good, thanks.

It's a cheap resistor; the same garbage you see all the time on eBay. What it does is trick your ECU into thinking the air coming into the engine is cooler than it really is so the ECu will advance the timing more and increase the amount of fuel going to the injectors. You would almost surely need to run premium fuel so you don't get premature ignition of the fuel.air mixture, and your fuel mileage might suffer on top of that. Fact of the matter is you can get the same result by just advancing your base timing setting a couple degrees, but you'll still probably need premium fuel. Oh, and at best, whther you use the resistor or set the timing manually, you are looking at maybe 5 HP max, and that's probably wishful thinking.

Agreed, it's garbage. A buck or two worth of materials, sold for $25 to cheapskate suckers that won't spend real money on real mods.

Thanks for the feedback, appreciate it.

Mark

BTW, the only computer modification I know of that is reputable comes from JET Performance. It is a true reprogramming of your factory ECU and is customizable based on your other modifications. It costs $400, so i would only do it if you have other mods. The gains seen without other mods probably wouldn't be worth the cost, but with mods it would probably have a noticeable, though not huge, impact on performance. Large gains are only seen with turbocharged engines. keep in mind though that this reprogramming would likely also require the use of premium fuel, since part of the reprogramming is more spark advance. I currently have a K&N intake and Gibson exhaust and have the JET program on my list, but probably not until I at least get headers and the larger throttle body.

http://www.jetchip.com/

"I currently have a K&N intake and Gibson exhaust and have the JET program on my list, but probably not until I at least get headers and the larger throttle body."

http://www.jetchip.com/[/quote]

Hi there, you mentioned headers and throttle body. Is there a company that make a streetable set of headers ???? Think i had a source here somewhere for throttle body.:cool:

Anyway, TIA, Ed in NJ.

No, one source for headers for the 00-04 Xterra, and they're not emissions-legal. The odds of a legal set of headers ever being available are slim to none.

Of course if you have no emissions testing where you live.......:D