P0138 error and misfires?

I just got a P0138 code with a CEL. Techstream says

"Oxygen sensor circuit high voltage (bank 1 sensor 2)". The monitor test results are a little odd because it shows 5 misfire status fields for the 4 cylinder engine. You'd expect it to go from 0 to 3 or 1 to 4 but it goes 0 to 4. They showed:

EWMA MISFIRE: 1
MISFIRE RATE: 4

EWMA MISFIRE1: 1
MISFIRE RATE1: 5

EWMA MISFIRE2: 0
MISFIRE RATE2: 0

EWMA MISFIRE3: 0
MISFIRE RATE3: 2

EWMA MISFIRE4: 0
MISFIRE RATE4: 0

I searched for this code here on the site but nothing was clear. Is this one still ambiguous or is there some clear way to approach it now? If there's an approach, what is it?

The engine feels like normal to me so far so no obvious symptoms.The cat was stolen in 2020 so the downstream sensor is new.

Thanks.

 

Hey,

For some reason the error cleared itself. I thought to screenshot but hoped copying the info on misfires would have been enough.

Don't know if it was because of repeatedly starting and moving the car small amounts without running it long enough to heat the catalytic converter. Here's to hoping the error doesn't return.

 

This makes sense, I guess. I hoped the lack of "rate 0" meant just "rate" was overall.

Thanks Dolj, I was hoping that guess about warming up was correct. I appreciate the thorough engineering of these cars but it's not always fun to work on them so I'd rather not need to.