all over ebay are these performance chips that seem completely exaggerated. do these things do anything? anybody have any experience with them? i would imagine that they could mess up your electronic system on the truck. heres an example:

eBay Motors: #1 PERFORMANCE CHIP FORD F150 1990-2009 1992 1991 (item 220375132948 end time Apr-08-09 10:26:28 PDT)

 

Thet are nothing more than a resistor in a plastic container. They my produce a small amount of power simply because it makes the computer misread a sensor, depending on the resitor an placement. (I really doubt 200 HP) but for the money you can look on here search 10k, or 14.k mods as a lot of the guys here build their own from radio shack for about $3, not $25 plus shipping.