So today saw a heap of success, but ended in failure.
I tried communicating with the MPPS V13 software.No joy as before. I was also supplied with V12 software so figured I would give it a go. Wham, straight up it was working perfectly. Reliable reading of the ECU ID. Did an ECU read and saved my maps. Yay!!!
Then, wrote the original file back to the ECU. That moment when it says "Erasing Flash" is always a butt tightening event, but the write went well, I held my breath the entire time, and the engine still ran. Yay once more.
So I head up and made a simple change. Similar to what AdrianD did early in this post with the 0% throttle IQ amounts, but I left only the 950 RPM value at 5. In my mind this should soften the approach to idle, but still give me the "deceleration fuel cut-off" I am looking for. Either way, it will test my ability to successfully do this job.
Verified the changes in WinOLS. All looked good. Fixed the checksum and verified again. The checksum changes now showed up in WinOLS too. Awesome I say. Time to go write it into the ECU.
Now I am back to where I was in the beginning. Can't read the ECU ID, Can't do a full read. Program just crashed the moment it tries to read.
So I am giving up for the night.