I had the same problem as xeyedjohn, thought I had bad gas because it started having issues after filling up with fuel. Same trouble lights were on and engine was misfiring. Stopped for something to eat and it wouldn’t start at all. Had it towed 100 miles home to my dealer. Dealer said it was a blown fuse in a panel that controls many things including the lifters or something on the cylinders which was causing the misfires. They said it is becoming a common problem and the gm engineers are trying to figure out why the fuse is blowing. They replaced the fuse, gave it back to me, ran great for a day and started doing the same thing this morning. I’ll give an update when I hear back from the dealer again.
