I'm using a 96-98 Hx harness on my 96 ek for my Ls-vtec swap. I notice that there are some wheres that are unused. I know one of them are for the EGR valve! But whats the rest for?? Whats the difference between the EX and HX harness??

 

I haven't personally dealt with an HX harness, but what I do know is the HX is simliar to an EX harness, the difference is that an HX uses a 7-wire 02 sensor, so you will need to mod the HX harness for 4-wire 02 sensor use. I don't modification info on this though, sorry.

Other than that and the EGR (which you can leave unplugged), it's pretty much the same harness.