Bought a 97 odyssey where the engine locked up. I paid a guy to swap a f23 into it but I don’t think he did it properly. I have the time now so I want to get this swap done right. So far I know I have to get the right engine harness and the ECU maybe.? I’m just not sure what steps are next, this would be my first attempt by myself .

 

You can use your original harness but you will need to add wires for the VTEC solenoid and the VTEC oil pressure switch to the ECU. For the ECU the best option would be to source an ECU from an F23 Odyssey.

 

Original Ody engine is F226 or 8, non VTEC.
F23A1/4 are VTEC, F23A5 is non VTEC.

You did not state which F23 is installed.

This will determine your course of action.

I would not look for an F23 ECU, it requires security, which is a whole ball of wax you don't want.

 

it is a f23A1, i went from non-Vtec to Vtec. The f23A1 trans rebuilt before the swap. So far the engine runs “okay” can’t really say since I only connected the stock harness and took it around the block. Idle is horrible though

 

By adding wires is that just pinning the connectors to the right socket.? Or do I need to splice into excising.? Tried looking a bit into this but haven’t gotten far

 

This is an engine swap, not an engine replacement and it needed a bit more research before doing.
If you can I would HIGHLY suggest having the original head rebuilt and reusing it and the original intake/exhaust manifolds. There is a bit more to this swap than simply adding VTEC y01111

Your issues are as follows.

You need a VTEC ECU
You need an OBDII ECU
Your gonna need to either remove your security function(blinking green key) or reprogram when installing the new ECU

Most likely the best ECU to use would be an 96/97 Accord F22B1 EX AT ECU. This will have VTEC control(F22B1), work with the OBDII system, have security, and IIRC the '97 Ody still uses the H4A(MPJA) transmission.
You will still need to run wiring for the VTEC oil pressure switch and VTEC control solenoid, as well as whatever differences there may be with F23A1 an F22B1 wiring. If you can find an ;96/97 Accord EX F22B1 harness that would probably save some time. And then still have to reprogram or delete the security function.

IMO the easiest solution would be to find another F22B2/B6/B8 or even a 98/99 F23A5 cylinder head. Put that on your already installed F23A block and use the Odyssey original intake and exhaust manifolds.
This allows you to keep useage of the original ECU, no need to program for keys, or disable security, and everything is then mostly original when it comes to other parts.

With the work needed to change to make the VTEC work, it would have been better to go full on H22 VTEC or H23 VTEC.

Check that FAQ at the top of the forum for any additional engine swap info.
BTW, if this engine change was done in any are that requires emissions testing, you will need to verify that this swap is allowed. Ody F22/F23 vans never had VTEC.