Been thinking about this for a while and I wonder if anyone can give me some advice on this.
I don't know if I stated it before but when the fuel trims went wack the first CEL I popped was a P0171 system too lean. Cleared it and then started popping a P2097 Post catalytic bank 1 too rich. I have also noticed that my MPG estimator on the dash has dropped about 4 to 5mpg from where it normally sits. Car smells like ethanol when idling. I know its unlikely that either of the 02s have gone bad but isn't that one of the indicators when popping conflicting CELS like that? If so how can I rule out bad 02s?