I already replaced this thing many years ago, but now I have the same Code 12. Tried cleaning it. Nothing working.
I can’t find one made for 90-93 Integras anymore. However, the 90-93 Accord version is still made and looks like the same mounting shape. The harness is different but I wonder if splicing would work. Any thoughts on this?
I performed a search on Standard Motor (Products) for 1990-1993 Honda and Acura and came up with these part numbers. I stated the differences based on the pictures provided.
EGV531 - Vacuum port is not bent, and it has two extra tiny holes in the gasket.
EGV577 - No leading wire like OEM, two tiny holes in gasket.
EGV1018 - No leading wire like OEM, vacuum port not bent.
EGV525 - tiny holes in gasket
EGV527 - Harness looks different
EGV1283 - Harness looks different (Used on NSX)
I’m in the same boat as you with the code 12. Gonna try cleaning my EGR valve tomorrow, if that doesn’t work I’m probably just gonna have to nut up and buy myself a new EGR from an Autozone that’s about 30 minutes away because they’re the only location that has one in stock.
Edit: When I get to the junkyard again soon I’ll look into some accord EGR’s too and try to help out with this.
Maybe we can get some side by side comparisons.
Also could it be any of the lines to the EGR or the vacuum pump itself that might be clogged with carbon or would need changing if the EGR has already been swapped out?
You found a place that still has them? DAMN. I swear I was looking all over for a new one.
If they have more than I’ll pick one up for you and shoot it over 
Cleaned the EGR valve today and no luck. CEL turned back on. Gonna try replacing it, if that doesn’t work… I’ll hit up the junkyard and pull some Accord and DA EGR’s.
I’m hoping it isn’t an issue with the vacuum pump or anything. Have you checked yours?
So I tried looking up possible other problems outside of vacuum lines and other stuff and here’s what I also found. I’ll try this when I’m off this Sunday as well and report back… but what I found is that possibly the lift sensor is stuck open? (How to fix code 12 EGR lift sensor on Honda cars - YouTube)
Thanks. I’ll give this a shot too.
I’m afraid to “pop off” that top part but I think my valve is not stuck. I’m able to move the silver rod so I assume that’s the same thing as what’s underneath the black clamped part.
I’m about to get a vacuum tester to see if that can identify it. I also have the electrical troubleshooting manual so maybe that might provide some further insight. I’m hoping it’s not the ECU but I understand that’s getting old 
Vacuum tester indicated that EGR valve is fine (I did clean it out a few weeks ago). So it looks like its the EGR solenoid that’s faulty. When I removed the vacuum hose from it, there was a lot of white “stuff” around the inside, so perhaps if I’m able to take it apart and clean it out, it would fix the issue.
So far as I can tell, there’s no new replacement for it.
I bought a solenoid that is about the same size as the OEM one, but was made for multiple Fords/Mazdas. I will try to pigtail this and see if that fixes the problem.
No luck on my EGR here either still. There’s an auto 91 DB1 that just came into the junkyard near me too. I tried removing the EGR off of it last time but the nut is waaaaaay seized on there as well. I’m gonna head back with better tools to pop it off this weekend. Was planning to clean it and pop it onto my car and see if it changes the problem for me. If not, I’ll try taking it apart and document it. I was thinking of possibly having a faulty solenoid on my end too. Def interested in seeing how it goes for you!
Btw, I also tried swapping out the ECU for a new one I bought last year. That didn’t change anything.
I feel awful about having to cut and spice wires to make parts work though. I’m about $150 in with parts and have no idea if they’ll solve anything.
I swapped out the solenoid for the Ford/Mazda one. Reset ECU. The CEL didn’t come on and I thought the issue was fixed after driving longer than the usual warm up time. I let the car sit for about 30 minutes and then drove it again and the CEL came on! ARGH
Fine.
Swapped in the new EGR from the Accord. Given that I had to splice, I wired it as (NEW - old hardness):
Yellow - Yellow
White - Yellow/White
Green - Green
Ran the car this morning. CEL came on.
I’m at a loss. I think the only thing left to try is to find bad grounds and those are a friggen bitch and require a lot of digging around etc.
I’ll try the HELMs troubleshooting procedure again with the new components in. I guess I can still try swapping combinations for the EGR valve wiring because I’m not sure exactly which wires go where.
Now that it’s cooler weather I’m going to start driving this car again (it has no AC). First thing I’m going to try to fix the issue is trying different combinations for the wiring in case they aren’t the same as the OEM connection.
Combo 1: Y-Y; W-Y/W; G-G (CURRENT)
Combo 2: Y-Y; W-G; G-Y/W
Combo 3: Y-Y/W; W-Y; G-G
Combo 4: Y-Y/W; W-G; G-Y
Combo 5: Y-G; W-Y; G-Y/W
Combo 6: Y-G; W-Y/W; G-Y
it turns out I had some bad wiring connectors. I have to start over. 
Combo 1 – same issue.
Currently on combo #2 but I didn’t drive that car into work today.
Combo 1: Y-Y; W-Y/W; G-G (CURRENT) received CEL
Combo 2: Y-Y; W-G; G-Y/W
Combo 3: Y-Y/W; W-Y; G-G (CEL)
Combo 4: Y-Y/W; W-G; G-Y (CEL)
Combo 5: Y-G; W-Y; G-Y/W (CEL)
Combo 6: Y-G; W-Y/W; G-Y (CEL)
Maybe that Combo 2 is the golden one. 
Combo 2 also failure. 
I wonder if just giving the ECU what it needs — like whatever voltage the EGR valve would normally give – would be enough just to fool it into thinking the EGR is working properly. It wouldn’t be difficult to wire up something to output 3V just make the computer think everything is fine. I’ll have to check the Helm’s manual. I’m really tired of wasting my time on this.
Not a bad idea. One thing to consider however is that the voltage from valve position sensor on the EGR fluctuates depending on how open or closed the valve is. That’s why the code only happens upon first accelerating because the ECU is checking to make sure the valve has opened now, looking for a higher voltage from the sensor. Hopefully the Helm’s manual has more specific descriptions of the voltage the ECU looks for at different driving conditions and maybe it’ll be okay with always reading a higher voltage. This is a video I referenced where he does a voltage check: https://www.youtube.com/watch?v=cWkpdhUOBd8.