G force performance Chips Reduced fuel mileage, check engine light on, truck runs like crap, Internet

Got this chip in a timely fashion ( for being manufactured) the install instructions wanted me to test wires with a multi meter to get certain perameters which were not found after a hour in the freezing cold, contacted Clay at first he told me to hook to black and tan wires, that reduced my fuel mileage from 13.75 down 12.60 mpg with the check engine light on now, contacted Clay again and was told that GM does whatever with color codes so try the black and yellow,

they cant even give proper instructions to hook up an electronic device to your autos computer, that didn't work so I removed chip and now my check engine light won't go off and my truck runs like crap, as an electrician I understand this stuff and what this does is take your ohms ( resistance) and lies to your computer telling it the air intake is colder than it really is and changes the perameters so your timing steps up, the theory is ok but I do not believe this is a proper way to do its job, i opened it up and its made of a series of resistors, do not purchase this product!!!!!!