I have a 2012 A4 that will start but loses power and idles really rough then dies. I thought it was the mass air flow sensor but I tried a new one and it didn't work. There are no error codes currently but I have had P2188 system too rich at idle bank 1 fault before. I changed the O2 sensors last week and it ran great for a week and then started doing this. I checked the spark plugs and they didn't look great would that cause this and if so why isn't it throwing a misfire code?

Appreciate any guidance on what to check next.