My gauge is reporting around 9.78:1 AFR on average as of late. My ER is averaging 1.00 which supposedly is stoich, and my O2 Sensor1 wide-range Voltage is also stoich, averaging 3.32. (it’s a Corolla).

This seemed to come out of the blue for the last couple of trips. The engine seems to run fine. Snap tests don’t always respond as one would expect.

Air Fuel Ratio(Measured)(:1) avg = 9.78
Fuel Trim Bank 1 Long Term(%) avg = 8.72
Fuel Trim Bank 1 Short Term(%) avg = .30

Any ideas?

I am trying to make sense out of this but am a bit of a novice. I have been studying a lot but it still hasn’t all gelled yet.

Any help would be greatly appreciated.

Thanks.