I can visually see the throttle blade opening all the way but I haven't checked it with a scan tool or tuning interface. I will check commanded vs actual TPS with EFI Live. The truck won't rev high enough to build boost as it goes into REP immediately after starting.

Does anyone know where I can get a stock 2004 Silverado file for EFI Live? I'm going to update my injector tables but don't think i can modify existing tune with EFI Live because the last tuner used a Custom OS with HP Tuners. Does this make sense or should I be able to modify existing tune with EFI Live?

 

You should be able find the stock EFILive file here:
https://www.dropbox.com/sh/4ydh5wltk...s4SRJ9NGa?dl=0

You will not be able to edit the HPT tune without over writing everything with an EFILive OS.

Are you going to tune it with EFILive, or are you just trying to use it to troubleshoot?

 

U0107 relates to loss of communication, or data loss between the TAC module and PCM. Could be an issue with:
1. the dedicated data lines between the 2 modules
2. a ground or voltage issue resulting in malformed data pulses...check engine harness ground connection to block, battery to block, and battery itself
3. one of the 2 modules being powered while the other is not...for example if the TAC module remains powered for a while after the PCM is shut down(or vice versa) there will be a U0107 already present right at key on. In this case though you should be able to clear the code after key on without it returning until the next key off/on cycle.
4. Bad PCM or TAC module
5. Incorrect PCM or PCM OS/calibration