Hey guys! I am not familiar with all this Honda stuff but am trying to help my son do a motor swap. It’s a 99 Canadian SI (ex in USA) with D16y8 and auto trans. Motor had been swapped from previous owner due to blowing the old motor.

we bought a rebuilt D16y8 from a shop to put in the car as well as a manual tranny.

I am trying to find an engine harness to put in the car. To go with the manual we got a manual ecu 37820-P2P-C31 to replace the auto one that was in the car 37820-P2P-C92

now I have no idea what the core for the rebuild came out of it that matters?

I believe the new manual ecu is an OBD2a ecu? And am not sure what the old ecu is?

what do we need to day to make all this work and before I buy a new harness what ecu will work here?

 

37820-P2P-C92 is OBD2b, '99 model year

37820-P2P-C31 is OBD2a, '96-'98 model year

you want a 37820-P2P-A12 I believe (this is USDM part number) to make life easy. If there is a CDM specific ECU part number, the go with that. It should be listed as "99-'00 model year.

with that and the '99-'00 model year engine harness (32110-P2R-A00, USDM) the rest of the work is relatively simple mechanical changes: clutch pedal assembly, clutch hydraulic system, shifter and linkage, mount brackets, transmission, flywheel, flywheel bolts (flex plate bolts are too short), clutch, ect.

 

thanks for the info. The mechanical part we get I was just worried about the ecu and wiring. I will try to find another ecu I guess to keep it simple and more straight forward. Just want to make sure all the electrical connections work with everything and the under dash stuff.

 

Keep your stock harness, just buy the appropriate connector for the IACV (3 to 2 wire) and do the pin swap on the ECU.
https://www.hamotorsports.com/pages/...or-99-00-civic

You'll need to swap to a manual TB/Intake manifold (though I think you can drill and tap holes on the intake manifold for the IACV)

 

so the auto harness will work with the manual ecu? What do you do with all the extra plugs for the auto trans on the original harness??

we have a manual intake and throttle body so all good there.

 

Correct, just do the 3 to 2 wire IACV swap and keep the harness as is to get you moving. While it may not be clean, you'll have unused plugs in your engine bay from the automatic harness. I just zip tied them together and made sure they wouldn't get caught on anything moving. You will also have unused ECU plug from the automatic that will be left unplugged also.

You will need to get a subharness for cruise control, clutch interlock and the reverse lights. You can wire them yourself or buy the kit from Chuck chainz here https://honda-tech.com/forums/sale-1...ew%2A-3353245/

 

thanks for the info. Where can I get the 2 wire IACV plug?

 

I bought the plug on ebay, you can buy used ones too if you prefer OEM
https://www.ebay.com/itm/18538356469...Bk9SR-Ku6J-dZA