Type R Club of America

Just curious what options there are for a replacement ITR engine harness.

I assume the LS harness is used with a few modifications.

Anyone know if the EM1 Civic Si is a suitable alternative?

I am using an LS engine harness on my non VTEC Integra and am just running a subharness for VTEC directly to my OBD2b to OBD1 subharness because the cabin harness wasn't wired for VTEC. But with the Skunk2 intake manifold, everything lines up for the most part and I didn't have to do any wire extending. Everything fit better than when I tried using a GSR harness (when I was dumb and thought I could just plug it in and get VTEC). The LS EVAP is on the intake manifold on OBD2 cars, but b/c the Skunk2 IM doesn't have that, mine is mounted on the firewall and so it might work like how it is on a stock ITR if or might need slight extending

But I'm guessing the plugs in the engine bay that connect the cabin to the engine harness will have the knock sensor and the VTEC wiring and you might just need to wire those in from a custom harness if you want to keep it factory like? That is the part I am not sure what looks like on an ITR, but is missing on an LS.

You cannot use a em1 harness. The em1 runs through the firewall and has the ecu plugs attached. The integra plugs into the cabin harness at the shock towers.

Anything can work with time and effort. I fear even checking as I assume Honda has already discontinued this piece as well. Depending on your goals and priorities, I would search for:
1.) Matching OBDII* depending on chassis ('97-98 or '00-01) *Duh, but that was my priority when I went through this a few years ago
2.) GS-R matching OBDII* but note, the injector wire lengths are different to accommodate the double butterfly design
3.) LS matching OBDII* but note, VTEC may have to be wired in

Alternatively, an aftermarket harness could be an option, depending on your priorities. There were a number of brands in the past but note, even the "reputable" brands led to a number of issues for users like myself.

just a heads up, most of the "big brands" that make wire harnesses sub the work out to mexico and then just put their labels on them. so sometimes colors or entire wires will be off and you can spend a lot of time chasing an issue that is because of the harness. there are a few people that make harnesses by hand and do a really good job with pinning out and quality insurance, and i would go that route first. usually similar prices but a little but more wait time.