I had the red lightning bolt hit me 2 days ago while cruising at 80 mph. The code I got had something to do with high pressure on the ETC controller (vacuum leak.) I didn't write down the exact code.
3 days earlier, I got 2 codes: Bank1 and Bank2 running lean. I strongly suspect these were false codes.
I will follow this thread closely. I need to take it to the dealer now, as I am installing a SC next week. Once the SC goes on, everything will be blamed on it.
Based on the searches I have done, the issue could be a faulty ground wire (or negative battery terminal wire.) OR there could be a vacuum leak. I really don't know. But I also get the flickering lights. I'm leaning towards faulty ground.