Ok, so this appears to be the ticket for putting boost into a 2005 and older Trail Blazer or Envoy.
For those of you who aren't aware, the 2002-2005 don't use a MAF...they have this mish-mosh of an Alpha-N and SD setup. The primary VE table is based on Load, and not based on actual VE values. This simple fact makes it nearly impossible to rescale the tables for boost, and when the PCM sees boost it goes into Reduced Power mode. No fun.
So, everyone has said that you could go to a P12 PCM and you gain a MAF along with proper tables. With a MAF, a simple MAF-rescale should take care of the boost, and the other tables can be rescaled / modified as needed.
The biggest problem for this swap has to do with the suspect change to the CANBUS data bus in 2006. From the research I've done, this change only appears to affect the 5.3 V8...the 4.2 stayed Class 2 Serial. I've compared wiring diagrams between the 2003 and 2006 Envoy, and everything suggests that with a pinout change, the 2006 PCM should run the truck.
Anyone have any thoughts or experiences with this type of issue?