A few months ago, we had a discussion about the wideband versus narrowband O2 sensors, and how they might be useful for tuning.
In the most recent issue of
Grassroots Motorsports magazine, they have an excellent article addressing that very subject. They have a comparision of readings from both types of sensor/gauge (both sensors were in the exhaust at the same time) which is quite enlightening about the narrowband sensor, and they mention in the text of the article about how the readings from the NB sensor varied significantly when the mixture was essentially unchanged...
--DD
(Who really needs to get that WBO2 set up on his car!!)