I think the info in this post on Renntech is more accurate:
https://www.renntech.org/topic/32802-error-codes-p1128-and-p1130/
Lean condition detected by the primary O2 sensors that cannot be corrected by the DME.
Think: Too much air, or not enough fuel, or sensors on either end (MAF or O2) are reading incorrectly.
and here's a pic that was posted on Rennlist:
...not that I'm particularly smart on this, but I've been dealing with it intermittently over the last month on one of my cars.