Bad news, the 87 I added seems to be triggering some knock correction and reverting to the "safe" maps. Ignition advance multiplier is doing fine at 1.0, but I guess the car picked up a little knock or something. (EDIT: turns out "knock correction learn" refers to timing advance, so no knock, but my wonky fueling probably triggered the safe map?)
But even worse, the ECU seems to have figured out my lean burn shenanigans
I was driving along the highway and was super happy to see the mpg meter around 41 at 60mph (so actually 46!), but then my mpgs started going down until they were even worse than the stock map after correcting for the reading difference. I glanced at my OFT and I could see the AFR going down until it stopped at 12.5!
I took the closest exit and reflashed the map. Same thing, car learns to idle at 16.8, then it starts running richer and richer. I think it's the post cat O2 sensor correcting the intentionally skewed readings coming from the front O2 sensors.
I've also decided that the weird engine behavior with a low idle target is a little too freaky with the nearly stalling and loss of electrical power. If I press the brake hard the engine stumbles, if I turn the steering wheel hard (electrically assisted) it also stumbles, and it keeps bouncing up to 700 and then down again. I'm going to try 600 for a bit and if I don't like it I'll go up a little more.
I've switched to a mostly stock map until I can review the logs in detail. That 41mpg carrot that got dangled in front of me has got me motivated, but I may have to physically cheat the post cat sensor to let the car run lean. Maybe 16.0 would be more acceptable to the engine and wouldn't trigger the enrichment.