When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
It will allow you to trick the ECU into thinking it is seeing less air/fuel so you can add more fuel and air while keeping a stock like idle. In the DSM world it will keep you from hitting fuel cut and for our cars limp mode.