I forgot that I had summer fuel in my 82 (my tank was filled in June). It dropped below 20F and gelled up while I drove. Had to coast to a parking lot.
D'oh!
If you are filling regularly, the local fuel should be blended for the temperature. Some additive never hurts, though.
I'm assuming that is a GMT900 thing then. 800s do not have that feature. I'm actually glad I don't have it because there's several reasons for low rail pressure other than a plugged filter.
Yeah, I would probably get super annoyed with that. It needs an undo that resets the life back to whatever percent it was before. I've set low rail codes a couple times due to weak CP3. But really, once I dialed the tune in, I don't have it happen, so probably a livable "feature".