Ive got a 97 ex and will soon be swapping in a B16 in place of my current LS. My current harness is a bit mangled so i figured i would start fresh. Since the SI came with a B16 i figured it would be a good choice and i found one for a decent price.

I know the ecu plugs are different but will everything else match up like the dash harness?

 

nope, it wont work

99 has the plug in the underhood fuse box

your 97 ex harness is perfect for the B16 already just do a few minor adjustments and it will work

 

I am currently running a 00 EX harness in a 96 hatch. I wouldnt advise doing it either to many problems have arised after my doing so you'll have a lot of wiring issues that you will need to sort out. Right now my problems are No back up lights, dash accesories not working, Speedo and tach wont operate, Engine runs but poorly at that. Fuses are blowing left and right so on and so forth. Just do yourslef the favor fix up your current harness and use that or find any D series harness and modify it.
Edit: I also forgot to add in right now I have replaced the alternator with one known to be in working condition and the battery isnt getting a charge so unless you feel like buying a new battery every week I advise against it that much more.