Riptide101

I am trying to find out if I can do this swap as cheap as possible and am wondering if this will actually work or if someone has tried this specific swap. I have a 98 4-door GS-R that my wife recently had an accident in. She ran over a small boulder and needless to say, they totaled and salvaged the car. I had full coverage on it, so the insurance company paid me a couple of grand for it because it was in such good shape. With parts being easily swapped from one car to another, I purchased a 94 Civic coupe.

I recently moved t another state and stopped by a local shop asking about the swap. They mentioned I would need a OBD1 P72 ECU, distributor, among other things to change it to OBD1. They said this would be the easiest route to go.

I don't really want to buy all these parts and the route I would like to go and don't know if anyone else has done this is use just about everything from my GSR and move it over. ECU, engine wire harness, mounts, sensors, etc. I have read elsewhere that the engine harness will plug right into the civic fuse box, minus some plugs. Does anyone know if that is true? I was also looking to purchase one of these to still use my current GSR ECU. OBD1 to OBD2A ECU Jumper Harness|HA Motorsports

What I am looking to see is if anyone has gone this route, and if so, did anyone have any problems that came up that was not obvious. I really don't want to go crazy with buying a bunch of things to make this work since this will be my daily driver. I may put bolt on later down the road but I am not looking to do much else to the car.

SpeedRacerEX-R

Yes, it's been done before. If you're not in a place like Commifornia, you're going to want that OBDI ecu. OBDII sucks.
But, if you're hell bent on it, you should have all the parts necessary to make it work with the exception of the jumper harness.

Riptide101

Trying to figure out why you said the OBDII ecu suck. I just assumed it was better to have the OBDII ecu because that's what the engine and sensors are. What are the benefits of having an OBD1 ecu besides just being able to plug the ecu in. I wanted the check engine light to work as advertised. This will be my daily driver and was looking for as unmodified as possible. If there was a problem with something, I didn't want to have to do a whole bunch of troubleshooting. I plan on moving the entire exhaust from the Integra to the civic. I told it is the same exhaust

NVturbo

it SUCKS because you CANNOT tune OBD2 ecu's (minus K-Pro)

/thread

SpeedRacerEX-R

Exhaust is the same, but you'll have to lengthen it.

JRCivic1

Using the OBD-2 ECU will require you to wire up items that do not exist on your '94 Civic EX... specifically, the CKF (crank fluctuation sensor), Secondary O2 (after cat) sensor, EVAP/purge vent canister pressure valve (requiring a different charcoal canister next to the battery), and a tank pressure sensor (which would require pulling the sensor out of the GSR tank, drilling the proper holes in the civic tank as well as running the proper vacuum lines)... all for the SAME performance as the OBD-1 ECU !!! If you use everything from the '98 Teg,except the ECU, it will essentially plug in at both shock towers and you will only have to run two wires from the passenger side engine harness plug junction with the chassis harness into the cockpit to the ECU... they would be the knock wire and the IAB control solenoid wire. So, do yourself a favor and do it this way... you won't have "check engine" lights for emission related stuff and the car will drive great. You will still have OBD-1 function so you can still check codes... even if it is the jumped service connector - flashing MIL light counting way. Remember your car doesn't have an OBD-2 "diagnostic port" in it anyway... you would have to wire that up and place it somewhere in the car as well to use it with the OBD-2 ECU.

Did I mention using an OBD-1 P72 ECU ??? Oh, and like NVturbo said... if you ever want to "tune" the car, you will need to convert back to OBD-1 anyway, so do it now and save yourself a ton of heartache and find a '94-95 P72... or better yet, socket your P28 and get a Hondata S300 and you won't have to run ANY wire from the engine to the ECU... just turn off the knock sensor in the tune and run a vacuum line directly from the I/M to the IAB vacuum disc bypassing the solenoid and vacuum canister under the intake manifold.

Good luck.

Riptide101

Thanks. This was the exact explanation I was looking for when trying to see and differences between using the different ECUs


.
Do you know this for sure? I have been all over this site as well as others and they are all saying they are exactly the same size and length when placed next to each other. Anyone else know if there is a difference?

Riptide101

Does anyone happen to know if these 2 exhausts are the same and bolt up properly with no modifications? Someone mentioned earlier I may have to lengthen it.