**Edit** Never mind, finally figured it out. Took a five minute breather and had a eureka! moment.
I'm trying to set up a histogram to correct my MAF configuration. I've tried just about every one I can find on the board, and every last one of them gives me a 'histogram not supported' error.
This is on a 1998 Camaro PCM.
Any pointers? Been jerking around with this all day and getting nowhere.