A/F/R gauge for tuning

I have an innovate dual wideband on my boat and an aem wideband in my truck. Both turbocharged and both would be a nightmare to tune without the wideband o2s. One thing I will mention that hasn’t been said yet is to verify results of ANY tool and learn to trust or discount those results. I KNOW for a fact my o2s are accurate because I verify what they say by checking the plugs. Once you learn to trust the sensor you’ll know when it’s lying to you and when it’s not. If you don’t verify the afr readings by reading the plugs then all you have is numbers on a gauge.