ok, so heres my situation. i got a b18a1, pr4 ecu, b17 harness. so that harness has no plug for EGR, and i am getting a CEL code 12(EGR System). I have looked at several DIFFERENT “PR4 ecu pinout’s” so idk what one is correct. But i am going to have to run my own wires from the EGR valve to the ecu. But i dont know what pins they are, havent found a pinout that looks correct. i found this one, http://www.phearable.net/tech/wiring…schematics.gif but those pins for EGR are the wrong color wires, and it says its for dif cars. And as of right now i cant pass emissions, idle emissions are tooooo high. And this is supposed to be my DD, but i cant get tabs until itll pass emissions, it has kept me from work more than is acceptable. i cant seem to find an accurate pinout. i dont know where the hell to turn lol, so hopefully someone on here can help me. PLEASE, and THANK YOU.
The EGR has two wires…
Black/Yel and Red (or Green on some cars)
The Black/Yel wire ties into the Evap Solenoid and Fuel Pressure Regulator Control Solenoid, which both run to the 15Amp fuse #24 in the Under-Dash Fuse Box.
The Red (or Green) wire goes to A20 of the ECU Harness.
My DA Haynes manual, and most pinouts I’ve found say the wire is indeed Red… But for some reason the diagram that I hand made from a while back lists the color as Green. I’m pretty sure the OEM color in my '93 LS is Green.
So far, this seems to be the best information I’ve gotten. I will check it out when I get home. Thank you. Very much haha.
UPDATE: came home, popped the hood… My EGR has 3 wires coming from it…? one green, one yellow, one yellow/white. so now, im back at square one. any ideas? the motor is out of a 90 ls i believe. did the 90-91 have 3 wires possibly?
Heres a pic:
Damnit… when I used my manual I looked up the wiring for a 92-93 lol. Yes, thats more than likely the issue… Let me find my manual on my computer and see if I can find the '90-91 stuff.
This covers part of the wiring… I left my manual at work. I’ll see if I can swing by later and pick it up and will relay the info I find.
Thats some good info, now i just need to figure out where the wires all go to haha… ok cool, let me know. and thanks for helpin. the most help ive got besides this is “unplug the vacuum lines” which doesnt make a difference considering its not hooked up lol.
Update…downloaded a manual, found out where the wires go. And found out egr was on auto cars only??? But anyways, out of the three places the wires go in, one is unused. The other two, have the same color wires but are for different things… this car is giving me hell. Everytime I think I solve something, more comes up. What a headache lol.
Only the auto G2’s had an EGR valve. I’m assuming that 90 B18A and ECU are out of an auto. I had a 91 before that the previous owner had swapped in an auto ECU for some unknown reason. I always had a code for EGR and then found out that was the reason. I believe I had popped the ECU open to find out that it was an auto. Something about a slot on the board being blank on manuals, but had something there in the auto’s. I don’t remember the specifics, it was a long time ago. I’m not sure if the B18a you swapped in is from an auto? Is your car originally a 5 speed? If your car is a manual transmission, I would think all you need is a manual transmission intake manifold and ECU. You might even just need some sort of block off plate for the EGR, along with a manual ECU (to get rid of the EGR code).
hmm… Yeah, i have a db2. previous owner blew the b17, kept the ys1. but yeah im gonna assume he got the ecu/motor out of an auto. i had another ecu, but a “friend” stole it… my boy owns a shop, is there anyway he can make that ecu work? or do i just need to get a new one. and if so, just a block off plate would do the trick im sure. but without that, my idle emissions will still be high im sure. that will fix the cel problem, which i also need fixed to pass emissions, but what other things should i check to lower my idle emissions? it passed everything else, has a new 02 sensor. the PO did put a rod thru the block, im sure the cat was FULL of oil, ran it alot. rebuilt the bottom end, no smoke what so ever. could the cat still be nasty and causing the idle emissions to be too high?
90-91 ECU wouldn’t work in a 92-93 (90-91 = OBD0, 92-93 = OBD1), so the previous owner might have gotten the motor out of a 90 but the ECU from a 92-93. I’m not sure how the inspections in your state work. Here in NJ, the CEL can’t be ON for vehicles that are 94+ (last time I checked). The only reason I mention that is because as long as the block off plate is eliminating the EGR & all vacuum lines are routed properly, the car should run fine. Like I said before, I ran my 91 with the EGR CEL & it ran perfectly fine. It only had the code because it was looking for a sensor that didn’t exist in a manual. I don’t know if your catalytic converter is bad after what happened. I can recommend using a bottle of fuel additive called “Guaranteed to Pass” that’s made by CRC. It got my HC’s down from about 300+ at 2500 RPM, to 72 at 2500 RPM. It’s not a miracle worker, but it helps. My buddy tried it to pass inspection in his 91 SER that had a hollowed out cat-converter and it obviously did nothing for his situation. What emissions are causing you to fail (NOx, HC, or whatever else they test for in WA)?
Well, he said it was from a 91. Had the harness from it and it was the same plugs as the b17 harness, isn’t that obd1? It coulda been out of a 92-93 I don’t think the PO knew much about cars.yeah, it runs great without the egr I just can’t test with a cel so I was gonna get a manual ecu so it wont look for the egr, so there would be no cel. My cat didn’t really look all that bad, and I’ve ran it a lot since then, and burnt most if not all the stuff out I would think. I think I actually have some of that stuff from my last car but never used it. Not sure if its the same brand but its called guaranteed to pass I believe. May have to give that a try. I’m not sure off the top of my head, I dont have the paper on me. It was my low idle emissions, so whatever that is. Idr if that NOx or HC.
Sorry for the very late reply…
The manual lists the following:
Grn/Whi connects to the same Grn/Whi wire as the TPS/ECT sensor/IAT sensor.
Yel/Whi connects to the Yel/Whi wire on the TPS
Yel directly to ECU.
If your ecu is indeed supposed to be running the EGR Valve Lift Sensor, it should be fairly easy to wire up yourself. Tap into the wires mentioned above, and run one new wire to the ecu. Just need to find a pinout of the auto ecu (or whichever ecu is designed to use said setup) and run the wire accordingly.
Okay, I just wasn’t sure if I was gonna ruin something by splicing the wires. Can’t I just plug em all into the ecu? Since that’s where they all end up? I have the pinout and everything. I may try this, I was thinking about just buying a manual ecu so it wouldn’t look for the egr. Car has high idle emissions. But it runs great. I will probly try just splicing into those wires tho, before I spend money on an ecu.
Yes they all run to the ecu… but how are you going to fit two pins in one pin location? The wires are spliced together, from factory, to once ecu pin. Splicing into the wires yourself is going to be doing the same thing, save for the yellow wire.
Naturally a manual ecu would be the best bet.
yeah, i think i will just get a manual ecu and make a block off plate or something. Is there any other things i can try to do to make it pass emissions, rather than the cat and “guaranteed to pass”?
edit: it doesnt really matter what year the ecu is for, as long as it is obd1 pr4 for a manual. Correct? because i hear that 90-91 is obd0, but my motor has all obd1 stuff on it and has an obd1 ecu at the moment…
http://www.hondata.com/techecuid.html
^ Some good ECU references there.
I’m not 100% sure if just any OBD1 LS will work properly. The reason I say that is because I know if you put a 90 ECU into a 91, it will throw a code for BARO sensor. The 90 had it mounted externally behind a kick panel and the 91 had it built internally into the ECU. However, both are OBD0 and the plugs will match up.
The type of EGR you have a pic of only came on cars with Auto tranny. Is your ECU for a Auto tranny?
Yeah, that’s why Its throwing the code. I need to find a manual ecu.
Bump!
Copied my post from another forum, maybe i will get some responses here…
well, after a short break from my car…im ready to start messin with it again. im sure you guys have heard my situation already but yeah…
Car runs GREAT…drove it shortly today, and no CEL came on…im sure it would have after a while considering its looking for an EGR i dont have…but no other CEL’s or anything. It doesnt smell as rich as before, although i havent done anything. Gonna have my boy convert my ecu to manual so it wont look for the EGR, so that will fix that CEL… but i still need help with my emissions…the O2 sensor appears to be like brand new…what else could be making my idle emissions high? Funds arent really in line right now to spend money on a gay ass new cat…but if need be, i guess…heres my sheet:
