As title says.
In terms of AEM EMS UEGO, PLX R-500, and AFR tuning... what is "wideband"? Thanks!

 

"Wide"band as opposed to "narrow"band. This refers to the range of measurement of the air/fuel ratio based on oxygen sensing of the exhaust gases. A narrow band instrument gives a range of readings that is very hard to read as it doesn't concentrate well enough in the critical range of what you need to see the A/F and use it for tuning.
For example the stock O2 sensor is a type of narrow band sensor. The AEM UEGO instrument takes a more specific range of the readings and "widens" it so that the numbers can be seen better and used for tuning purposes.
Narrow band gauges typically are those "Christmas tree" lights you see that flicker back and forth and are hard to pinpoint a specific number. They only give a generalized range of a/f. Wide bands can give an actual number that is more reflective of the a/f in the exhaust at any given moment.
Try a Google search for "wide band O2 sensor" and see if you get a better explanation than what I've just attempted to give.

Here is a narrow band gauge:


Here is a wide band gauge:

 

What you said is what I figured. Common sense should have told me, based on the name itself. Just wasnt sure if there was more to it than the gauge reading or not.
Could have just PMd again! Thanks a lot.