Fuel Saver Chip - do they work?

seen a seller on ebay offering a chip to improve fuel economy, hp, etc.

says it is a "chip" some of his neg feedback claim it is only a resistor and does no good.

Are there any "chips" that do work? are they street legal, etc?

It's complete crap. It's fact that they don't work. Just to be 100% sure I bought one, and made it switchable. My car was noticeably slower with it and I'm sure my gas consumption was way up when that thing was on. It's basically a 50 cent resistor that "fools" your computer. I think the Honda engineers knew a little more than some guy who knows how to solder and has a Ebay account. Save your 5$ for gas.