Don't worry about the 1280 code, it was prolly caused by the 10k mod. When you did the resistor or whatever method you used, then the signal was prolly interrupted at some point and caused the code and light.
The code started about three months after I took the 10K mod out.
Here are the numbers I got from driving it.
ICP Idle Driving on Cruise at 60 Cruise at 65 WOT