What is the deal with these. They are sold on ebay.... of course.... Do they actually work or harm? What about the cheap power modules for like 20 bucks? They sound like a 20 dollar trip to a new motor. Heres a link to the "ebay power" upgrade.

http://cgi.ebay.com/ebaymotors/18HP-...spagenameZWDVW

 

resistors literally cost 2-5 cents and those "power modules" are just resistors in plastic casings. i guess in theory they would work because they fool the computer into thinking that the air coming in is colder. and more dense. colder air gets more fuel, so your truck runs rich. of course thats theory and essentially you remove the computers ability to actually measure the air. your gas mileage will suck, you will get carbon build up faster and probably plug up your O2 sensors. driveability will suffer too

 

Yeah I knew the cheap resistor part, but I think its funny that they sell them like they do...

 

all it is doing is slightly advancing your timing and making you run a little richer.