[Shane@DBPerformance]

Narrowband O2 sensors like the stock ones are only accurate at 14.7:1 A/F ratio. When you get even half a point away from there, they are wildly inaccurate. Wideband O2 setups are usually very accurate all the way from around 10.0:1 or lower up to 19.0:1 or higher.

Widebands also aren't a simple power, ground and signal setup like a narrowband. They require a controller box to run them, which is why they are more expensive. A wideband O2 sensor on it's own can often be cheaper than a stock style O2 sensor, but you need a controller to run it.