well, did all the same things as other times ive tried it but i unplugged the brake controller, and pulled the fuses out of his HIDs. It let me pull the factory calibration just fine, built the dsp5 tune and it wouldnt let me full flash. Kept sayin no response from ECM. I then did something I've found worked on another 05 LLY. I did just a quick basic single tune, flashed it in, drove it to make sure it worked fine, then went back and full flashed the DSP5 in. works like a champ!!
Why would doing a regular flash of a single tune work and then seemingly "open the door" for a full flash?? I'm just glad it worked.
Thanks all!!