Re: 97 Civic EX to HX conversion
 

A few more parts gathered:

1. An ECU from a 97 HX Fed emissions 5-spd:

https://www.fuelly.com/attachments/fo...3c0c59f714.jpg

2. The '97 ECU with an engine wiring harness from a '00 HX CA emissions 5-spd:

https://www.fuelly.com/attachments/fo...2241469038.jpg

3. A set of final drive gears, 3.722 ratio (18T on countershaft, 67T on ring gear):

https://www.fuelly.com/attachments/fo...e63b5f5a7b.jpg

4. A pic of where this will be taking place, once I find the rest of the parts.

https://www.fuelly.com/attachments/fo...a2d28ec92c.jpg

Re: 97 Civic EX to HX conversion
 

ECU won't work with that harness (96-98 OBD2A, 99-00 OBD2B) they don't use the same plugs, am I right?

Re: 97 Civic EX to HX conversion
 

Yes, if we were talking about any other Civic from 96-00 you'd be right.

But the HX didn't switch to OBD2b like all the rest - it stayed OBD2a right through 2000. You can find verification of this at other Honda sites with a search. And yes, the wiring harness plugs into the ECU perfectly - already checked that out for just in case.

More updates to come - HX wheels are installed, but waiting on a clutch before doing the tranny teardown and regearing, and waiting on some final bits for the engine before going ahead with that.

Re: 97 Civic EX to HX conversion
 

Great info, jbi. But I'm wondering if a D15 would make more sense. Parts are more readily available and cheaper. I had a 97 HX, which was great. The O2 sensor went out, which cost me $350 at Honda (with a friend discount). Ouch! The exhaust mani cracked as well.

I was getting 46 MPG (mostly all freeway, as I have a 100 mile commute) with no hypermiling stunts. Right now, in my 97 EX, I'm at 37MPG. With a D15, I'm willing to bet I'd be in the low 40's. If you figure in the lower maintenance cost, that would be the way to go, IMO.

Good luck with your swap. I love these Civics and would get another 96-00 Civic if this one gives up the ghost. But only at 190k miles right now.

Re: 97 Civic EX to HX conversion
 

Also should add, with an HX 5-sp transmission, it would close the gap even more. It'd be intereting to see how they would actually compare...

Re: 97 Civic EX to HX conversion
 

Sorry, I don't know if I am able to edit my posts, but can't seem to figure it out.

Digging through my old spreadsheets, it looks like I was getting about 50MPG on the HX, not 46 as I stated above.

Re: 97 Civic EX to HX conversion
 

Sorry for the long time period between posts, but things here have changed. My wife decided she wanted a newer vehicle, so I put the swap on hold after gathering almost all of the necessary parts. The only things left that I need are new parts that go along with the install - clutch, timing belt, etc.

So now I'm left with these parts, and I'm either going to keep them as spares for my HX, or sell them as a lot if anyone is interested. I'm really bummed, as I'd looked forward to this project.

If anyone is interested in buying these parts as a lot, you can post here or PM me. I will be advertising them locally as a lot as well. Sorry, I'm not interested in breaking them up and selling them individually.

If there is real interest, I'll list the contents of the lot and come up with a price. Thanks! -Joe

Re: 97 Civic EX to HX conversion
 

If you need, this might help you. I made it the other day for a friend who is putting a VX in a CRX.

https://eastcoasthondas.com/pictures/ntk-l1h1-pinout.jpg