I'm going to install a proper water temperature gauge.

I was going to remove the factory temp sensor and place the new one in, but some of my reading suggests that the ECU uses a signal from the factory sensor. My engine manual in in Japanese, so it's difficult to understand.

Does anyone know from experience if I can simply swap the sensors over or do I need to get some sort of t-piece or even one of those metal adaptors that you place in the top hose?