From what ive been reading if i get a jdm 13b then i need to use the usdm wiring harness and ecu is this correct? I just dont want to mess something later if im wrong.

 

That depends on the year of the JDM engine. The core engines are the same. However, some of the components around the engine have changed over the years. Also, JDM engines generally do not come with some of the emissions equipment that US models did.

For the most part, the answer to your question is YES.

 

I thought that you had to use the JDM harness and ECU with a JDM motor.