Well that's not at all true, unless you've found a specific sensor I'm not familiar with. For the wideband to function as a switching, narrow-band o2 sensor, the controller has to simulate the voltage output of a narrow-band. If the controller has dual outputs, you can run it as a narrow-band and then also read the wideband output. This is true of the Innovate one I suggested. That wideband controller's output then also needs to go into the computer somewhere (the EGR sensor input is often used), or directly into the tuning computer (if it has serial output) where it can be used in conjunction with the other EEC outputs in data-logs and to perform the tuning onto a piggy-back chip. By itself, installing a wideband O2 sensor in place of a narrow-band isn't going to do anything for you, and won't work to replace the narrow band for the purposes the computer uses it. In a tune you can just use one narrow-band o2 sensor to manage both banks, and then use the other bung for the wideband, but it still needs a controller and a way to get its voltage to the computer used to tune it.
In every case, a controller is required. A wideband also won't physically plug in where a narrow-band does. You don't need a gauge if that was the point of your post, but as most kits contain one for not much more $ than the sensor and controller together, you might as well see the output.
