02 sensor base tune

[Briefx]

Is a 02 sensor needed if I’m running a base tune on open loop. Sorry if this is a stupid question. Will a base tune even work on open loop? Due to no tuning and no adjustments

[Spunkster]

Without tuning there is no way you will be able to tell if it is running a safe AF ratio. If you do not have a wideband then you will be unable to make adjustments based on a reading.