For Harley-Davidson motorcycles every O2 sensor equipped Harley has an option of two different EJK controllers based on user installation preference. The user can select to just use O2 bypass modules to plug into the factory O2 connections or they can choose an O2 plug-n-play controller where the unit plugs into the O2 connectors much like the injectors. Functionality for the controllers is the same! Users choose the bypass modules for easy installation as a result of less harness to route along the frame. Users choose the plug-in harness for a cleaner look where nothing is left unhooked and zip tied up out of the way.
Figure 1 - Shows an EJK controller with O2 bypass modules on the side.
Figure 2 - Shows an EJK controller where the O2 connectors are part of the harness.