Rep Power: 0

Long story short. I have a 2005 civic with D17a1. Car was totaled but engine was recently rebuilt and still good. I bought a donor car that had a bad motor. It’s a 2003 civic that had a d17a2. Both are automatics. I want to swap my good motor and install it into the donor car that had the vtec motor. Am I going to have to change the ecu also in this situation ? Anything else I should be aware about? I still have the car that was totaled so I can still take the parts off it if needed.

 
Rep Power: 512

Yeah, you're gonna have to swap the ECU or you'll throw a P1259 code and it'll throw the car into limp mode.

Transmission will bolt up just fine. The D17A2 transmission will have shorter gears and accelerate faster if you decide to go with the donor car tranny. Not sure how the immobilizer is going to play though.

 
Rep Power: 224

Will need to have the keys programmed to the ECU or swap the ignition cylinder/immobilizer ring as well. But then you have a different key for door and ignition.

 
Rep Power: 0

motor swap went well. I swapped ecu and harness. Only issue I’m having now is one code.

PO135
02 Sensor _Heater Circuit Bank 1Sensor 1

i have replaced the 02 sensor with a factory one
( 36531-PPA-305 ) and even tried one from my friends car. It comes on within 5 seconds of resetting and starting the car. Any advice would help! Thanks

 
Rep Power: 512

did you keep your OEM ECU or use the 03 ECU? On the 04-05 model years, Honda switched to a wideband upstream O2 sensor compared the the 01-03 narrowband O2 sensor

 
Rep Power: 0

I swapped the ecu from the 05 into the doner 03 car. Engine, harness and ecu