Feuling 12mm Narrow Band O2 Sensors For Harley Feuling O2 sensors are on the money with a ceramic body made of stabilized zirconium dioxide surface coated with gas permeable platinum electrodes and a porous ceramic to aid the prevention of erosion due to contamination and particulates in the exhaust gases. Features: Precision manufactured with a ceramic body made of stabilized zirconium dioxide, surface coated with gas-permeable platinum electrodes and a porous ceramic to help prevent erosion due to contamination and particulates in the exhaust gases Slow reading oxygen sensors can cause a drop in fuel economy of 10-15, excessive exhaust emissions and poor drivability Meet or exceed OE specifications Note: Front fits 2010-2016 / Rear fits 2010-2025