Well back to square one, I drove it withe the o/p unhooked and it made no difference on my original problem but the open reference code hasn't come back yet

 

Plugging the opsu in shouldnt cause difference in map voltage.... I would need to find a wiring diagram to find whats common between them.... What is your map sensor reading vs the BARO pid (inHG) key on engine off??? They should be the same check them against barometric pressure in your area

 

Well the 5v ref for both sensors are on the same circuit along with one more i think. so i can imagine if voltage was less that what it should be it would effect the MAP signals to the ecm. But my problem hasn't occurred again so it was either that, maybe the ecm had to relearn the correct paramiters for the MAP? I also thought maybe my problem was torque converter shudder so I put a also all amount of shutter fix in the trans.

 

Interesting may have been the shudder.... Glad it seems to be fixed!!! post updates if returns!!!