Ok so I have read a ton of questions about CEL about octane or issues with low fuel. I was having issues with a soft code if my fuel got low. Basically if I had the low fuel alert and then refueled, if I gave it 3/4 throttle whilst getting on the freeway I would have a CEL show up. It would then disappear and show up again if I gave it juice. Took to audi and found out it was a faulty fuel sensor. The codes that show up will either be low fuel or a wrong octane ping. So if anyone is having trouble with this and cant find the cause, this may be worth checking out.