I ordered the "piggy back adapter" from pcmforless and I need to locate the pcm/prom whatever to get this done. They have an installation guide but I don't see what they are talking about. If someone could either explain it or point it out in a picture of a thirdgen it would be greatly appreciated.

 

remove the passneger side plastic on the bottom of the dash and look up. piggys backing ias a bad way to go BTW>