Well Holy Sh!t. I thought the ecu error sounded sort of familiar. Turns out I had a P0601 5 years ago that i forgot about and even mentioned in a post.
In that post, the car had sat for 2 years waiting for a new engine and after installing one, I had some starting difficulties because of a clutch switch problem. In the process of troubleshooting, I found I had a P0601 and had even called a shop about replacing the ECM. I do recall doing doing a re-write entire then as well as part of my troubleshooting and hadn't seen it since.
It would be okay I guess if this was just a once in 5 years type of thing that a full-rewrite can continue to fix. Though in reality, this will make me feel like I'm driving a ticking time bomb that will leave me stranded at an inopportune time and thus I will just stop driving it, so it's not exactly ideal.
And yes, Nothubertjfarnsworth, the 2 bar OS is a custom HPtuners OS. Perhaps it has some quirks? I have always gotten a service vehicle soon light on every start that I just assumed was due to the OS since I have no codes.