All good. after we found a hose that popped loose, zip-tied it. installed new 3-port boost unit. reflashed to new map, reset ECU. still throwing same P0170 running lean for days.
went back to shop, we immediately saw another hose / wastegate, had popped off. no ways we would both have missed that the first time. my guess is that it hap'd after we installed the 3-port. more boost? anyway we fixed that, reset ECU.
idle is finally stabilized (since I bought the car, really...) CEL is gone, crazy amount of power and dare I say it the thing is almost too fast for my taste. it's way more speed than is even useable on the street, at least, in the crappy crowded boring roads of Miami...
i think the car is officially bonkers now. sounds like chirping parakeets and goes like a rocket. just, no stickers rims bumpers flames etc three more datalogs today, finally moving on to next tune map...