ok.. update

pulled the oil pan from the transmission and the fluid was nice and dirty.. like a brown red color. I found some odd "brown" flakes of some sort at the bottom.. I'll have a picture of that later.. hopefully it wasn't something important.

Replaced the oil filter and refilled it and even replaced the cooler someone installed, prior to my ownership, and installed a new "high performance" one in front of the condenser to help against the wonderful Texas heat.

Drove it and so far it's shifting without noises and fairly smooth. I am still having a random stall at idle which is annoying, but it may be a sensor somewhere that I haven't found. The CEL even went off this morning as I drove to work.

I am hopeful that this fixes my transmission for now so I can move on to other fun stuff.