Hi, I have a 93 Prelude Si, came with the H23a1 and i swapped the H22A into it. everything ive researched both obd1 ECU's should be interchangeable.. as far as i know the motor i have is obd2. it definitly has a knock sensor and two spots for an oxygen sensor but as far as ive researched the serial numbers on the block matched up to obd1, which confuses the **** outta me. when i bought the motor i also got the harness to the fusebox and ecu but the rest of it was cut, it also goes up under the dash. as far as i know a p13 ecu is definitly obd1 and it plugs into the harness that came with the motor and my car is obviously obd1 and came with a p14 ecu. but the ecu's will not interchange with the plugs that are in the car. im wondering if anyone knows if someone makes an adapter harness for that or if im gonna be stuck cutting and splicing the other ecu connectors? theres no way i can get an entire new harness its a hard car to find in CNY especially for parts and im not paying over $1k for a new harness from the dealership. Any help is appreciated, thanks.

 

can you try that again in better sentence structure so it makes some sense?

i THINK you swapped in an h22 into your 93 si. direct bolt in, plug the original harness in and then add the 3 wires for vtec and you should be done on that side.

then if you have an obd1 p13 ecu plug it in and go.

if you have an obd2 p13 then it will not fit and you can sell it for a lot more than the obd1 ecu to someone in cali that needs it (or some other emissions state) and buy your obd1 p13.