Wideband Question
 

Did a search but to no avail...

Does anyone know if there is a significant difference in readings/accuracy between the wideband sensor that goes into the O2 bung and the sensor probe that is put into the exhaust; like on a dyno.

I can't say for sure, but the one they stick up the tailpipe is probably a heated sensor just like a regular WB.
I've seen DIY kits that use the same sensor that you would put into a bung used as an up-the-tailpipe model.