I have 2 Zeitronix Zt-3 Wideband O2 Kit (just the sensor + controller, not the gauge kit). Both kits are used.

One kit is in nearly perfect shape. Used very briefly before I moved to a Nemesis that has a built in wideband controller. 130$

One kit works perfectly, but had a small mishap with coming unclipped and rubbing on the exhaust for a brief bit. As a result, the O2 sensor connector clip is melted. Still works 100%, but doesn't look so pretty at that clip. 100$

 

Price Drop: 110$/90$.