what does an aem ems have to do with an ecu that has hondata installed?
aem ems is a great standalone engine management system for somebody who needs the ability to tune there engine in virtually every aspect imagineable. it is not for the faint of heart and is highly recommend that you find someone who can tune with this unit before you consider buying one. although it does work just fine, most people would rather go with a hondata system or basic chipped ecu because tuners are more familiar with these type of systems.
now if you have a basically stock engine and are not planning on any major modifications then you don't need this, or anything like it. just stick with your stock ecu