Yes , you need the signal wire from the map sensor (green) to #2 terminal on the powerlogger board
Man...got a hair confused there for bit. I was thinking you meant I needed to connect the MAP signal wire back into the new PL circuit board that I just installed in the ECM. I was definitely doing some head scratching, all the while looking at the "PowerLogger I/O Connections" page that comes with the kit. Where the hell are those connectors? Definitely clued in when reading on the PL MAP connection here:
http://www.vortexbuicks-etc.com/PowerLogger.htm and seeing that terminal block...gave me a bit o' inspiration to look back into the box.

Didn't see that before! And now I know the reason for the other cable. I thought it was an alternative to a USB connector to the PC.
I sure do love learning! Anyway...I must say I'm attracted to the more simple method of just tee'ing into the MAP signal, and not getting into his more involved wiring...hoping that the signal will be accurate.
But it sounds like I need to upgrade to a 3-bar MAP? I'm currently at 17 psi, and hope to be going higher soon. Kirbans...$80!!! Or can I get away with the OEM MAP for now?
Also...anyone analyzing my PL run should notice that I did have some hesitation as it shifted into *3rd* (at frame 561). Basically, once it did, it stayed put at 4K rpms, and obviously flat powerwise. So...still some issues to address.