How to fix Code 12 (EGR) on H22 swapped 6th gen

I know the Code 12 (EGR fault) is a common problem in OBD1 H22 swaps on our OBD2 Accords. Some people say to just use the F23 EGR, but this is incorrect. All an F23 EGR will do, is cover the hole on the Intake.

I have recently swapped my H22 into my 99, and I was plauged by the code 12. I previously did some searching and found no real fix for it. I live in AZ, an state where emissions on 96 & up vehicles is done by scanning.
After doing a lot of wiring diagram reading and Honda service manual reading. I have successfully fixed my EGR and will tell you how to wire it up correctly.

There are 3 critical components to make the 92-96 EGR work:
1. The EGR Valve lift sensor (the part bolted to the motor)
2. The EGR control solenoid (activates the 3rd part)
Honda part #17290-PR7-A01
3. The EGR vacuum control valve
Honda part #36190-P13-003
#2 & 3 are normally bolted to the body of the car under the hood.
There are also the connecting hoses between the 3 parts, Which includes hard and soft vacuum lines.

If you are missing any of these, or have them incorrectly wired the ECU will set the code 12.

If you were unlucky enough to only get your engine seperate from the other parts, You can search the junkyards (goodluck) or goto a Honda parts department. You can get the control solenoid & Vacuum control valve for about $150. The vacuum lines can be rigged up, with some bulk hose and vacuum fittings. I was lucky enough to have all the parts since I pulled the motor myself.

Below is the EGR system Diagram pic (Honda Svc Manual)

Above is the pic of the other parts required to make the system work correctly.

Warning: I take no responsibility if you don't know how to splice & solder wires. Remember to disconnect your battery before doing any of this, and as a precaution I suggest disconnecting your ECU from the harness to prevent any shorts.

If you have all these parts, the hard part will be wiring the system correctly to connect to the ECU. Assuming you have the H22 EGR valve lift sensor installed (part on intake), first cutoff the F23 EGR connector (5 wire connector) from the harness. Make sure you leave enough wire to splice onto.


Next you will need the connector from the H22 harness for the EGR valve lift sensor. Wire colors are GRN/WHT, RED/WHT & WHT/BLK.
You also need the 2 pin connector for the ctrl solenoid. Wire colors are BLK/YEL & RED.

Side note: If you dont have the correct connectors, find some connectors on the harness that fit. I had to do this and lookup the pinouts for each sensor. Hopefully you know how to do this, I don't wanna explain it here.

Looking at the F23 harness you just cut the EGR connector off of, locate the PNK, GRN/BLK & WHT/BLK wires.

#1 PNK connects to H22 EGR control solenoid RED wire. This runs to A11 on the ECU.
#2 GRN/BLK connects to H22 EGR valve lift sensor GRN/WHT wire. This runs to D22 on the ECU.
#3 WHT/BLK connects to H22 EGR valve lift sensor WHT/BLK wire. This runs to D12 on the ECU.
#4 BLK/Yel wire on the EGR control solenoid needs to be hooked up to 12V battery power.
#5 RED/WHT on the H22 EGR valve lift sensor is tapped into the YEL/RED wire on the MAP Sensor. DO NOT cut the wire off the MAP sensor! Just tap into it. This runs to D19 on the ECU.

The remaining 2 wires from the old sensor can be capped off & tucked away.

Lastly Refer to The 2 pictures above to hookup the vacuum lines between the valve lift sensor, the cntrl solenoid & the Intake manifold.

Congratulations if you can successfully do all of this. I know it was a pain in the Azz for me. But I am on a mission to pass emmissions. Whoa that ryhmed.

Pic of H22 EGR valve list sensor
Note the wire from the EGR to the MAP sensor. (That red thing around the wire is just a heatshrink marker, I used it to remind me the color the wire should be).


Pic of the Control solenoid valve & Vacuum control valve. I bolted mine in place of the Cruise control, which is the connector you see dangling on the bottom.

Very Nice write up. I've been trying to find some information about how to do this for some time now.

What ECU are you running, OBD1 or OBD2b? I would assuming you are running OBD2 since a chipped OBD1 cannot communicate with emissions scanners.

At the top you mentioned that using the F23 EGR valve will not worked because I think the ports do not match. Would you think it would be reasonable to fab an adapter plate for the ports and then just run the F23 EGR?