I have an 06 trailblazer LS 4.2 4x4 and have swapped the engine from a 2007. Every since completing the swap I have been stuck in power down mode. After taking it 2 mechanics and a gm dealer I was told that the computer was bad. I replaced the computer with a new unit programmed to the vin of my 06. I used my original 06 wiring harness and noticed a couple differences on the accessories so I just swapped my original accessories to the new engine. I keep throwing codes for throttle body voltage to low. I have replaced the throttle body, accelerator pedal, mass air flow sensor. I am thinking of replacing the engine harness but my gut tells me there is something more to it than that. Where there any changes between 06-07 that would cause these issues for mixing the years computers and harness? Any help will definitely be appreciated.