OBD2 conversion

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busdriverj

New Member
Ok, yes this is my first post on this forum. However, Ive been on and off reading threads for about a year. That and I just spent the last 2 days search every forum about this swap.
I recently bought a friend of mines totalled 2000 Civic SI. Its a fully built and boosted 1.8 liter B16 (sleeved and bored for those confused ones). All this was running on an AEM EMS.
I have a 90 CRX SI that I want to put all this into. Being the engine is already built and tuned on AEM, I wanna keep the OBD2 sensors/wiring harness/ECU. How would I go about doing this? How would I adapt the OBD2 Ecu and eng harness to the cabin obd0 harness? Im confused on the conversion harnesses the companies like Rywire sell. Does this soley allow a obd2 ecu with all obd0 hardware or is this the ticket for me.
Any and all help would be greatly appreciated. I plan on time attacking this car in next years Redline Time Attack circuit and the d16a6 isnt going to do anything for me.
 
What you'll do is keep your stock engine harness and use it on the b16. then you'll need an obd0-obd2b ecu conversion harness.
Rywire - Online Store

one side will plug into your stock interior harness and the other side plugs directly into the ems. theoretically this should work just like if it were a stock obd2b computer. I cant vouch for it with absolute certainty though since i am not sure if the ems will be able to do all the things it did before, through the conversion harness. if no one else can clarify you might want to call up rywire and see what they have to say.

oh and also to clarify, a sleeved and bored b16 will not make it a 1.8l or even close. a stroked b16 would effectively make it 1.8l however
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Ok, so I run the EF harness? How about the alternator and dizzy? That means those will be OBD0 too?

I understand what you're saying about the harness adapter. Ill give them a call next week and talk to them about it.

I forgot to say stroked too, lol my bad. I had to do a head gasket on it a while ago and it was for a GSR.
 
the alternator plug i believe remains unchanged whether its obd0, obd1, or obd2. you can't use an obd0 ecu, the dizzy has to match the ecu. i dont believe they make an obd0-obd2 b-series dizzy adapter (atleast i sure as hell can't find one) I found this for a d-series..

Rywire - Online Store

and below it you can see a link to click for an obd0-obd2 b-series dizzy adapter. but if you click on it, it says product not found...

it just makes it all quite confusing having to maintain all obd2 electronics. generally the idea is to stay obd0 or obd1 if you can. its just easier, and there are many tuning programs for obd1, where as not so much for obd2. your pretty much left with a standalone unit as your only option, i.e. probably why he purchased the aem ems to tune the damn thing lol.
 
Well you're just full of accurate information tonight...

You cannot use the stock harness from the 2000 Si, or any car for that matter other then the one that came stock with your car. how do you propose he connect all the obd2 engine harness plugs to an obd0 harness
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Whenever you do an engine swap you ALWAYS retain the stock engine harness. The only exception is if you're swapping in a k-series.
 
look asshole, no one asked for your smart ass remarks, keep them to yourself. he has the ems, humm obd2b in a obd0 lets think about all the extra wires hes going to need to run. lets look at the fact that his car was made in 1990, humm.. 18-19 years old.... yeah that wirings is going to last. If he wants to save himself some headache, he will swap the entire harness, then its plug and play. Not a rats nest of cut wires.

O and btw d16sihatch your little info on the tranny in the other post is incorrect so take you head and shove it up your ass
 
Whoa now guys, easy. Well figure this out without blood shed.
I would love to retain the OBD2 engine harness. It goes straight through into the car and plugs into the ecu, does away with the jumble of wires on the strut tower. But, if that's not going to work, so be it.
I would do a EK dash harness but all the interior is already gone(he started parting out before I bought it). But that is an awesome idea. I could do an EK cluster swap at the same time. Just the task of finding that harness.
But for now, I'd like a simpler method and still retain OBD2. Ill call Rywire tomorrow and talk to them about it the adapter.
I should have thought about the dash harness swap a long time ago. I work for TopSpeed in Atlanta and I just did 2 full STi swaps into mid 90's Imprezas. Basically the same thing except I had 2 complete donor cars. Worked well, but takes forever.
 
look asshole, no one asked for your smart ass remarks, keep them to yourself. he has the ems, humm obd2b in a obd0 lets think about all the extra wires hes going to need to run. lets look at the fact that his car was made in 1990, humm.. 18-19 years old.... yeah that wirings is going to last. If he wants to save himself some headache, he will swap the entire harness, then its plug and play. Not a rats nest of cut wires.

O and btw d16sihatch your little info on the tranny in the other post is incorrect so take you head and shove it up your ass

yes please, insult me with your wisdom. the profanties are a nice touch as well. really helps get your point across..... tell me, have you ever actually done any research for these claims you make. have you done any work on your vehicle, or do you have others do it for you? Anyone who has ever done a swap or taken the time to research what it takes to complete a swap would have learned this. you Always retain the stock harness, sole exception being if you are doing a k-swap. You don't choose to retain it because you want to save money, or because you think the harness you have is in decent enough condition, you keep it because thats quite simply how it's done. If you can't understand why an obd2 harness will not plug into obd0 harness plugs then you're actually less intelligent then i originally gave you credit for. It is not plug and play. an obd0 engine harness is p&p with an obd0 cabin harness, which oddly enough is why you keep the stock one... who knew
emhammer.gif


You also said my information is wrong about the tranny? i'm pretty sure i've owned one personally and i know what the sole electrical component on an EF manual trans does. its a reverse light switch. plain and simple. not to mention your misinformation about the speed sensor. all ef's utilize a cable driven vss (i.e. no wires) besides the jdm sir which utilizes an electrical vss. and i already stated even if he had an electronic vss, its 3 wires, not 2. so please don't try and "school" me. If you don't know what your talking about then don't spew misinformation. i don't pretend to know everything either, which is why if i'm not sure about the info i'm giving i make that point known in my post, rather than make a statement like i am 100 percent sure of it when i'm not. you should try the same ;)
 
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where did I state about plugging a odd2 harness into a obd0, hes using a ems for tuning where the hell do you suggest he hook that up to if he goes back to obd0. He has the entire car, all the wiring for the b16, why complicate shit. pull the entire harness for the b16 and swap everything. And please dont talk like you know shit. The EMS will NOT WORK ON OBD0 there are too many variances, including wire gauge and the amount of voltage running through the lines for sensors, not to mention all the extra wires you will need to run, plus all the sensor clips you will need to chop and run. Do it the right way, not the half ass way.
 
seriously you can't comprehend what i'm telling you? the harness on the engine has to remain obd0 so that it can plug into the obd0 plugs on the shock tower, get it? at the harness connections in the car where the ecu is you would then use an obd0-obd2b ecu jumper so that you can plug in the ems. the jumper then gives you the extra connections you don't have on the stock obd0 engine harness (i.e. knock, vtec, 4 wire o2, etc). as far as i can tell you are suggesting using the b16 engine harness but as i've already stated countless times it has obd2 plugs on it and will not work with the obd0 shock tower connections. the only way he could possibly use the stock obd2 engine harness, which i dont think has ever been done in such a way, is to change the interior harness as well to the ek's harness. course if he did that it will no longer plug into any of the connections for the dash. meaning he would have to swap the whole car to an ek dash and run the whole car as an ek. i really don't think that's what he is trying to do.
 
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The only way he could possibly use the stock obd2 engine harness, which i dont think has ever been done in such a way, is to change the interior harness as well to the ek's harness. course if he did that it will no longer plug into any of the connections for the dash. meaning he would have to swap the whole car to an ek dash and run the whole car as an ek. i really don't think that's what he is trying to do.

Actually in post #8 I mentioned that sounded like a good idea. Ive done such things in Subarus many times and a Honda wouldnt be any different for me. Ill still retain the EF dash and heater box and all, just the harness will change. Then run the EK cluster. Then I would just adapt the A/C controls and the lights switches and such. Would take a while to do, but no biggy for me.

I was hoping that there would be a much easier way but its not looking that way. If I could use the OBD2 harness I could get some money back by selling the D16A6 with the harness and all, uncut. This will be a heavy used track car and I dont want too much splicing going on with the engine harness. The light switches and such wouldnt be a big deal on the track if they mess up. Just lights, lol. However, this harness is already gone as so is the dash. Ill just go to a good junk yard and pick up a donor harness and cluster.

BTW, anyone know if the EK and EF dashes are the same width, that would be dope!!!
 
yea i saw you mention that but i figured you'd probably rather keep the ef dash and then just do an ek cluster swap. which isn't nearly as hard as doing a whole dash swap. i guess you lucked out then cause you represent the minority of people who would be trying to complete a swap like this (swapping out the interior harness) since your building a track car and not too concerned about every little thing working, aside from the engine bein wired properly. i have unfortunately not heard of someone ever installing an ek dash into an ef. i imagine if you have decent fabrication skills then it wouldn't be too difficult. assuming the ek dash will physically fit half way decent within the confines of an ef/ed.
 
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Yeah, thats the main thing for the dash conversion, is it the same width?? I work mainly on Subarus and they are insane for sit bolting right in. IE, a complete 07 STi drivetrain bolts directly into, say, a 95 impreza. Thats 12 years diffrence. The dash isnt as easy on those, but I can get them in. Ill look at my friends 98 Civic Coupe and see what the measurements are.
I still will have everything working. Im still gonna half way daily this car. Its not gonna be a trailer quenn by any means. Im just more worried about the engine electrical than the rest of everything.
I appreciate your help and iinput in this.
 
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