Go ahead and add me to the list. After 14,000 trouble free miles, I took the GC to the dealer for it's second oil change and a def refill (I was at 10%).... drove to work, stepped out for lunch and on my drive back the check engine light "Dings" on.
Plugged in the ELm and fired up dash commander and sure enough. P20EE!
Edit: called dealer and told service mgr my reader pulled the p20ee. He asked if it was driving weird, I said no, he then said it should be fine and wait to bring it Monday as they will have more parts in stock for what he calls the fix. I can only assume they have done this repair many times before by his reaction. Didn't ask.
I cleared the code. will see if the CEL pops up again.