tehteg

Hey honda-tech, I recently finished my first swap. We did a gsr swap on my 98 hatch. So first I will list some facts to help reduce confusion.

-98 civic dx (car)
-97 civic ex (harness)
-97 gsr swap
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Now for the Cel's Im getting;
10-> IAT
14-> IAC
54-> Crank
65-> Secondary O2
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I need help troubleshooting these codes. What did I do wrong/what's not plugged into what. If you could answer these questions and help me fix these codes I'd really appreciate it.

b18cKoupe

What obd2 ecu are you using...obd2a gsr ecu?

Check that you didnt swap the IAC and IAT sensor plugs. The iat plug on the civic harness is positioned near the intake arm and will need to be extended to reach the factory iat sensor on the gsr manifold. You can also leave the plug where it is and use the iat sensor from the ex intake and mount it in your intake. Im not positive if the plugs are the same but i think they are, they are definitely both 2 pin plugs.

Also are you using a 5spd ex harness or auto. The auto harness uses a 3 pin rotary iacv. they can be used but require some wiring changes and the proper two pin plug.

Do you have a secondary o2 in the cat, if im not mistaken since your car was a dx the secondary 02 sensor was originally in the cat that is on the exhaust manifold. I think the exs have the 2nd o2 sensor wiring on the chassis(under the car)and not the engine harness, so your new ex engine harness doesnt have the plug and your car(dx) doesnt have it on the chassis since it was on the dx engine harness. You will need to manually wire it to the ecu if you plan to stay obd2. Did you even plug anything into the secondary o2??

As for the crank sensor that is behind the lower timing cover, there will be a plug down there coming out near the pully. I don't know if the y8 had one or not, if they did the plug will be on your harness and you prob forgot to connect it. Generally speaking the obd2 usdm motors cane with these sensors so it should be there. Im just not sure if the obd2 d series came with them.

tehteg

-I'm using the obd2a gsr ecu I got with the swap. No jumper harnesses etc

-It is a 5 speed ex harness.

-I do have a secondary cat in the o2, the previous owner installed an aftermarket exhaust system on the d series motor and when he installed the header he got a cat with an o2 in it (car had no cel's while the d series was in). I got an o2 wire extension from the harness to the cat and yes it's plugged in.

-And for the crank sensor we attempted the crank sensor trick... Not sure where we went wrong on it or if there is a common mistake made when doing this.

tehteg

Bump

tehteg

Bump

b18cKoupe

it would be helpful to get the 5 digit sae obd2 codes with a cheap code reader or at autozone for free. They give more specific info like high/low voltage out of range/no signal etc. Much easier to troubleshoot.

HondaPartsHero

Ok heres my assumption of your codes. The IAT you probably don't have plugged in. The IAT plug for the DX/EX is a different style than the GSR. You'll have to swap plugs over by depinning your DX/EX plug and plugging it into the round style on the GSR manifold (see pic for style). For the IACV your EX harness should have a 2 wire already unless the harness was for an automatic (see pics to make sure its plugged in). For the crank angle sensor it should plug right in according to the pic unless your engine is an OBD2 JDM which I don't believe has this sensor but if so you can bypass it. Your O2 is going to be a problem because the EX harness doesn't have the wiring for that because the EX secondary O2 is built into the car harness and the DX secondary O2 is on the engine harness so you'll have to run the wiring directly to the ECU from the sensor. You can easilly solve a lot of problems by converting to OBD1 and eliminate the O2 code and crank code.





CRANK SENSOR


SECONDARY O2 HONDA 98 DX LOCATION



SECONDARY O2 LOCATION ACURA INTEGRA (OBD2) #26 in diagram