Auto parts store didn’t have both gaskets, and because of a bracket holding the exhaust together, I couldn’t just change one, possibly causing a leak on Bank2 for re using the gasket.
BUTTTT! The bank1 post cat sensor was the issue.
The new one instantly showed .7V on start up, which matched Bank2 sensor.
I am guessing the old sensor was internally shorting out(as someone previously said) or working intermittently.
Even though when it did work, it only got up to .4V, the DME didn’t like that .3V difference, or sensed something was wrong when the sensor would drop down to/stay at 0V.
0V must mean lean? So pre cat was trying to compensate with more fuel, giving the other code “too rich”.
and when the DME constantly saw 0V, it triggered bank 1 stuck lean and too rich?
That’s just what I think, I don’t know.
I did the drive cycle, all monitors ready and no more codes.
Thanks a bunch to everyone that helped!
