NAMZ started to produce our Oxygen Sensor Extensions since many customers had asked how they could fit their custom exhaust system from their 2009 FL onto a new 2010 FL models. The kit also works perfectly for ALL 2012 FXST & Dyna models allowing the use of older style pipes. The new sensors are also in a different location, much further back on the head pipe thus making the need for a longer harness. Our Oxygen Sensor Extensions allows the use of a 2009 header to fit onto 2010-up models and includes 18mm to 12mm bung adapters & a front Plug-n-Play harness extension to allow for easy installation. Our front O2 extension harness kits have been tested and designed by our engineers to work & fit perfectly. Simple installation and are intended to be installed with 2009 headers/exhaust systems & ALL 2012 FXST & Dyna Models.