I’m trying to determine whether I’ve a faulty front O2 sensor. What should I log in VersaTune to see whether there are strange readings coming from a failed front sensor? My MAF reading at idle is 4.58 and LTFT is around 19. There’s no option to log O2 sensor data directly in the menus.

From what I understand that MAF reading shows I found my vacuum leaks. I sprayed starter fluid at all the hose and gasket joints and was pulling the accordion tube behind the MAF while spraying it. I’ve also looked at the accordion tube with a light inside and saw no cracks. Hopefully proved no leaks.

 

The O2 sensor is self diagnosed while you drive, you'll get a code if it's bad. The ECU will vary the fuel amount to see how the sensor responds and if it doesn't respond as expected you get a code. It's not your sensor, you just haven't found the leak yet.

O2 sensors don't fail by reading high or low, they fail by not reading at all or reading erratically.

I don't think the wideband produces any OBD signal outside of voltage which is meaningless on a wideband) and the actual lambda (AFR) reading