I keep hearing mixed info on this so I was hoping someone could clear it up. I want to put a air/fuel gauge in my TT225 but I am not sure if it operates on a wide or narrow band O2 sensor. If it is narrow I here it is inaccurate anyway and I should upgrade to a wideband sensor. If it is already wideband can I get just a gauge? The AEM kits I am looking at come with a sensor as well. Can you just tap into the existing wideband (if it is wideband) without installing a new sensor as well? Thanks for you help

An air/fuel gauge is inherently innacurate regardless of whether its a narrow or wideband signal. If you want accuracy you want an EGT gauge. Much more reliable tool for tuning the mixture of your car.

I've tapped mine directly into the pre-cat O2 sensor wire under the car. It works, albeit the needle swings pretty wildly because the gauge is reading the instantaneous voltage off the sensor.

Sounds about right. They are OK to be an early warning of a problem, but essentially useless for tuning.

Thanks for the info. This is my first turbocharged car so I wasnt sure. I went from a 2.8 A4 to a VR6 Jetta to finally a TT. With the EGT, when the temp gets too high its running lean correct? What is considered the high point it shouldnt exceed? Thanks guys