OBD2 and OBD1 questions
Thread Starter
Honda-Tech Member
Joined: Oct 2007
Posts: 78
Likes: 1
From: AB, Canada
OBD2 and OBD1 questions
I'm planning on installing a 98+ JDM B18C engine into my '92 hatch, but I can't decide whether I should go OBD1 or OBD2. What do you guys suggest, and WHY? I hear that the OBD2 is a pain when it comes to upgrades, such as the "check engine" light comes on if after market Cam shafts are installed, and its tunability is quite difficult as well. On the other hand, I hear that if you install an OBD2 engine, wired up for OBD1, you will not be able to get the full potential out of it. Please help out! How difficult would it be to wire up an OBD2 engine for OBD1? (Oh, and passing smog is not a problem up here in Canada!)
GO GIANTS!
Joined: Apr 2007
Posts: 8,236
Likes: 0
From: WEB CELEBRITY
Re: OBD2 and OBD1 questions (Creepsjr)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Creepsjr »</TD></TR><TR><TD CLASS="quote">I'm planning on installing a 98+ JDM B18C engine into my '92 hatch, but I can't decide whether I should go OBD1 or OBD2. What do you guys suggest, and WHY? I hear that the OBD2 is a pain when it comes to upgrades, such as the "check engine" light comes on if after market Cam shafts are installed, and its tunability is quite difficult as well. On the other hand, I hear that if you install an OBD2 engine, wired up for OBD1, you <U>will not be able to get the full potential out of it.</U> Please help out! How difficult would it be to wire up an OBD2 engine for OBD1? (Oh, and passing smog is not a problem up here in Canada!)
</TD></TR></TABLE>
You pretty much summed it up man.
Bold I agree with and Underlined im not sure about.
I used my OBD2 wiring harness on my OBD2 JDM Motor and used a conversion harness to a OBD1 Chipped P28 if that helps in anyway.
</TD></TR></TABLE>
You pretty much summed it up man.
Bold I agree with and Underlined im not sure about.
I used my OBD2 wiring harness on my OBD2 JDM Motor and used a conversion harness to a OBD1 Chipped P28 if that helps in anyway.
Honda-Tech Member
Joined: May 2002
Posts: 3,601
Likes: 0
From: Oxford, MI, USA
Correction: tunability with OBD2 is pretty much impossible. There is nothing wrong at all tuning an OBD2 engine on OBD1 ecu, and nothing is required to be done as far as special wiring to the engine side unless your harness is missing stuff. Basically, anyone who is tuned is tuned with either a full standalone system or a modified OBD1 factory ecu, so whoever says you "can't get the full potential" with OBD1 is an idiot. OBD2 is what limits you from doing any serious mods.
Former Moderator
Joined: Oct 2001
Posts: 16,612
Likes: 55
From: Southside ATL, GA
Re: OBD2 and OBD1 questions (Creepsjr)
First of all the JDM engine will be OBD1 - period.
There are no true JDM "OBD2" engines. Depending on the year you get the engine may have OBD2 style plugs on injectors, alternator, distributor, etc. and maybe even the ECU plug will be the OBD2 A style, but it's still an OBD1 program that only looks for one o2 sensor, no catalyst efficiency crap, not evap system codes for loose gas cap, etc. etc.
My best advice would be ask for an engine with the OBD1 style plugs on the distributor, injectors, etc. and that way the swap will go more easily.
From there you can use your stock Civic engine harness and simply add the wires for VTEC, knock sensor, and IAB/secondary butterfly (if it's a GS-R style engine).
And as far as tunability goes, yes fuuck OBD2.
Modified by B18C5-EH2 at 3:35 PM 10/25/2007
There are no true JDM "OBD2" engines. Depending on the year you get the engine may have OBD2 style plugs on injectors, alternator, distributor, etc. and maybe even the ECU plug will be the OBD2 A style, but it's still an OBD1 program that only looks for one o2 sensor, no catalyst efficiency crap, not evap system codes for loose gas cap, etc. etc.
My best advice would be ask for an engine with the OBD1 style plugs on the distributor, injectors, etc. and that way the swap will go more easily.
From there you can use your stock Civic engine harness and simply add the wires for VTEC, knock sensor, and IAB/secondary butterfly (if it's a GS-R style engine).
And as far as tunability goes, yes fuuck OBD2.
Modified by B18C5-EH2 at 3:35 PM 10/25/2007
Honda-Tech Member
Joined: Aug 2005
Posts: 5,130
Likes: 1
From: San Jose, CA, US
Re: OBD2 and OBD1 questions (B18C5-EH2)
i have done the swaps numerous times. all you need is get the complete swap, get a obd-2 gsr harness or LS harness, obd-1 ecu chipped with a itr map, a usdm vtec solenoid, and everything else will work.
the harness will plug right up and into the shock tower plugs also. it is perfectly fine to run the obd-2 stuff in the engine bay and then into a obd-1 ecu. the reason for the usmd vtec solenoid is beacause jdm itr uses only the solenoid to activate vtec and no oil pressure
Modified by fmrprojects at 12:38 PM 10/29/2007
the harness will plug right up and into the shock tower plugs also. it is perfectly fine to run the obd-2 stuff in the engine bay and then into a obd-1 ecu. the reason for the usmd vtec solenoid is beacause jdm itr uses only the solenoid to activate vtec and no oil pressure
Modified by fmrprojects at 12:38 PM 10/29/2007
Former Moderator
Joined: Oct 2001
Posts: 16,612
Likes: 55
From: Southside ATL, GA
Re: OBD2 and OBD1 questions (fmrprojects)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fmrprojects »</TD></TR><TR><TD CLASS="quote">why if you order a 98 jdm itr swap they send you a obd-2 ecu. will that plug into a obd-1, NO.</TD></TR></TABLE>
Well I stated that the ECU will have an OBD2A plug, but actually is still an OBD1 program?
I own a Type R swap, and I briefly ran the stock "OBD2" JDM P73 with a jumper harness, but mysteriously it never threw codes for secondary oxygen sensor, catalyst efficiency, or evap system leaks even though I had no secondary 02, or evap ****.
THAT'S BECAUSE THE JDM P73 HAS AN OBD2 PLUG, BUT IS IN FACT STILL AN OBD1 PROGRAM!!!
Also the "OBD2" JDM B18C engines lack the CKF sensor, and the "OBD2" JDM P73 ECU doesn't even look for one.
What makes the engine and/or ECU OBD2 in the first place? It's not just the type of plugs that the ECU and sensors on the engine carry now is it? I'd consider an engine and ECU that only have/read for one o2 sensor, no CKF sensor, no catalyst efficiency low, no EVAP system codes, no bullshit "system too lean/rish" codes, etc. etc. all OBD1. The plugs on the various sensors for a 98 spec JDM ITR engine are like the OBD2 engines, as is the ECU, but they are in FACT still an OBD1 system lacking many sensors exclusive to OBD2 ****.
I did make the mistake when I replied was that I missed the "98 spec" in there, so I threw in some extra info that wasn't needed. I was trying to tell him to ask for an OBD1 type plug engine swap, but since he said '98 spec then the main point of mine is that the ECU isn't even really OBD2 even if the plugs are. Still doesn't mean I'd run it.
Of course I know an "OBD2" engine harness will plug right in - I wrote the book on that! Back when everyone was reusing their stock Civic harnesses and hacking up injector plugs, or using shitty old Civic ones on a Type R engine, etc. etc. I had already figured it out, posted it up back in 2001 or so, and got hammered by people telling me I was full of ****, so I posted pics, etc. to shut them up. Later on it's all over the net, etc.
My B18C5 Type R swap with full "OBD2" engine harness:
Modified by B18C5-EH2 at 4:30 PM 10/29/2007
Well I stated that the ECU will have an OBD2A plug, but actually is still an OBD1 program?
I own a Type R swap, and I briefly ran the stock "OBD2" JDM P73 with a jumper harness, but mysteriously it never threw codes for secondary oxygen sensor, catalyst efficiency, or evap system leaks even though I had no secondary 02, or evap ****.
THAT'S BECAUSE THE JDM P73 HAS AN OBD2 PLUG, BUT IS IN FACT STILL AN OBD1 PROGRAM!!!
Also the "OBD2" JDM B18C engines lack the CKF sensor, and the "OBD2" JDM P73 ECU doesn't even look for one.
What makes the engine and/or ECU OBD2 in the first place? It's not just the type of plugs that the ECU and sensors on the engine carry now is it? I'd consider an engine and ECU that only have/read for one o2 sensor, no CKF sensor, no catalyst efficiency low, no EVAP system codes, no bullshit "system too lean/rish" codes, etc. etc. all OBD1. The plugs on the various sensors for a 98 spec JDM ITR engine are like the OBD2 engines, as is the ECU, but they are in FACT still an OBD1 system lacking many sensors exclusive to OBD2 ****.
I did make the mistake when I replied was that I missed the "98 spec" in there, so I threw in some extra info that wasn't needed. I was trying to tell him to ask for an OBD1 type plug engine swap, but since he said '98 spec then the main point of mine is that the ECU isn't even really OBD2 even if the plugs are. Still doesn't mean I'd run it.
Of course I know an "OBD2" engine harness will plug right in - I wrote the book on that! Back when everyone was reusing their stock Civic harnesses and hacking up injector plugs, or using shitty old Civic ones on a Type R engine, etc. etc. I had already figured it out, posted it up back in 2001 or so, and got hammered by people telling me I was full of ****, so I posted pics, etc. to shut them up. Later on it's all over the net, etc.
My B18C5 Type R swap with full "OBD2" engine harness:
Modified by B18C5-EH2 at 4:30 PM 10/29/2007
Trending Topics
Former Moderator
Joined: Oct 2001
Posts: 16,612
Likes: 55
From: Southside ATL, GA
Re: OBD2 and OBD1 questions (fmrprojects)
BTW the rest of the info (besides the OBD2 ECU bit) is on-point and exactly what I would have initially typed up had I not missed the "98-up" part in the OP's original post.
Only difference is that there is a way to "trick" the P28 ECU into reading the VTEC oil pressure switch (which the JDM solenoid lacks) by looping a wire - Kenji Plennert knows exactly how it's done, and he also chips P28 ECUs to run the Type R engines VERY well. Mine made 176whp/130ft-lbs. of torque on his ECU program.
Lastly are we indeed talking the Type R 98-up B18C, or could it be the GS-R/SiR-G? He never specified. If it's the GS-R/SiR-G then the P28 idea is tossed in favor of an OBD1 P72 GS-R if he keeps the stock IAB intake manifold.
Only difference is that there is a way to "trick" the P28 ECU into reading the VTEC oil pressure switch (which the JDM solenoid lacks) by looping a wire - Kenji Plennert knows exactly how it's done, and he also chips P28 ECUs to run the Type R engines VERY well. Mine made 176whp/130ft-lbs. of torque on his ECU program.
Lastly are we indeed talking the Type R 98-up B18C, or could it be the GS-R/SiR-G? He never specified. If it's the GS-R/SiR-G then the P28 idea is tossed in favor of an OBD1 P72 GS-R if he keeps the stock IAB intake manifold.
Thread Starter
Honda-Tech Member
Joined: Oct 2007
Posts: 78
Likes: 1
From: AB, Canada
Re: OBD2 and OBD1 questions (Creepsjr)
Whoa, whoa... this is getting a little crazy.. So what you're saying is that the stock OBD1 ECU is fine to run the 98 Spec JDM B18C in my car? All I need is the jumper harness to go from the "OBD2" enginer harness, to plug into my OBD1 ECU? Also, I hear that everything is backwards in regards to the JDM engine drop, in terms of the wiring harness... What can I do about that problem? Is there anything I need to add/remove from the ITR harness?
I'm not gonna lie, I'm all new to the swap business, and want to be as prepared as I possibly can, rather then getting caught with my pants down half way through the swap, and realize my car isn't driveable for the next month or so.
I'm not gonna lie, I'm all new to the swap business, and want to be as prepared as I possibly can, rather then getting caught with my pants down half way through the swap, and realize my car isn't driveable for the next month or so.
Former Moderator
Joined: Oct 2001
Posts: 16,612
Likes: 55
From: Southside ATL, GA
Re: OBD2 and OBD1 questions (Creepsjr)
No jumper harness of any kind will be needed.
If you purchase a JDM Type R B18C engine this is what you'll want:
1. Make sure the swap comes with engine, transmission, axles, shift linkages, mounts, all sensors/plugs, hopefully the 98' spec JDM header, intake manifold, alternator, starter, distributor, fuel rail, injectors, etc. If it comes with an ECU that's great, but you won't be using it - sell it off online to someone with a newer car that can use it
2. The engine may not come with an engine harness - that's fine too
You will need to buy an engine harness ideally from any 96-01 Integra GS-R or Type R because they have a few extra wires imbedded in them for VTEC - worst case scenario would be if you have to settle for a 96-01 Integra LS harness and then add the extra VTEC wires
The reason why you need the 96-01 Integra harness is because the US 92-95 Integra and Civic engines and engine harnesses have completely different plugs on a lot of sensors and accessories than the JDM B18C and US 96-01 Integra. By getting the 96-01 harness you can literally plug the harness onto the JDM engine without having to hunt for any extra parts, or cut and splice any wires
Your car is a 1992, which means even if it's not a VTEC-equipped car from the factory it still has the VTEC wiring imbedded in the chassis/body harness, which means if you buy the 96-01 Intehra GS-R/ITR harness it will be a 100% plug and play swap.
3. For an ECU all you will need to do is buy a P28 ECU from any 1992-1995 Civic Si/EX - ideally buy a chipped one from a reputable source, or buy a stock one and send it to Kenji Plennert, chipper extroardinaire - kenji211@tampabay.rr.com is his e-mail. I ran my ITR withone of his P28s for years and it ran awesome.
4. If you need more details, like mounts, other misc. parts you'll need than I'm sure lots of people can help, but we'd first need to know what your swap actually came with or we may list a bunch of extra **** you've already got
Good luck
Oh and lastly two reputable swap sources are:
http://www.hmotorsonline.com
and
Import Auto Salvage - 1-800-962-8922 - ask for Larry Jr. or Randy, and tell them Tom from GA sent you
If you purchase a JDM Type R B18C engine this is what you'll want:
1. Make sure the swap comes with engine, transmission, axles, shift linkages, mounts, all sensors/plugs, hopefully the 98' spec JDM header, intake manifold, alternator, starter, distributor, fuel rail, injectors, etc. If it comes with an ECU that's great, but you won't be using it - sell it off online to someone with a newer car that can use it
2. The engine may not come with an engine harness - that's fine too
You will need to buy an engine harness ideally from any 96-01 Integra GS-R or Type R because they have a few extra wires imbedded in them for VTEC - worst case scenario would be if you have to settle for a 96-01 Integra LS harness and then add the extra VTEC wires
The reason why you need the 96-01 Integra harness is because the US 92-95 Integra and Civic engines and engine harnesses have completely different plugs on a lot of sensors and accessories than the JDM B18C and US 96-01 Integra. By getting the 96-01 harness you can literally plug the harness onto the JDM engine without having to hunt for any extra parts, or cut and splice any wires
Your car is a 1992, which means even if it's not a VTEC-equipped car from the factory it still has the VTEC wiring imbedded in the chassis/body harness, which means if you buy the 96-01 Intehra GS-R/ITR harness it will be a 100% plug and play swap.
3. For an ECU all you will need to do is buy a P28 ECU from any 1992-1995 Civic Si/EX - ideally buy a chipped one from a reputable source, or buy a stock one and send it to Kenji Plennert, chipper extroardinaire - kenji211@tampabay.rr.com is his e-mail. I ran my ITR withone of his P28s for years and it ran awesome.
4. If you need more details, like mounts, other misc. parts you'll need than I'm sure lots of people can help, but we'd first need to know what your swap actually came with or we may list a bunch of extra **** you've already got
Good luck
Oh and lastly two reputable swap sources are:
http://www.hmotorsonline.com
and
Import Auto Salvage - 1-800-962-8922 - ask for Larry Jr. or Randy, and tell them Tom from GA sent you
Thread Starter
Honda-Tech Member
Joined: Oct 2007
Posts: 78
Likes: 1
From: AB, Canada
Re: OBD2 and OBD1 questions (Creepsjr)
My 98+ JDM B18C swap includes the following:
Engine
5 Speed Transmission w/LSD
ECU
Uncut Harness
Distributor
Alternator
Intake Manifold
Exhaust Manifold
Fuel Rail
Injectors
Throttle Body
All Bracket and Sensors
Air Conditioning Pump
Intermediate Shaft
Power Steering Pump
Axles
Linkage
Header
My '92 Civic IS equipped with VTEC (Si hatch), and for now I will be sticking with the stock integra/civic mounts. But Isn't it true that the JDM harness is meant to plug in on the opposite side of the car as compared to the USDM version? What happens with that? Do I splice into the Type R harness, and extend the wires so as to reach the other side of the car? And also, I hear that the plug ins on my stock P28 are completely different then the Type R plugs themselves..
Sorry if this is taking a little bit to sink in, but I'm doing my best to learn this stuff, and its pretty hard until I actually do it myself... thanks B18C5-EH2!
Engine
5 Speed Transmission w/LSD
ECU
Uncut Harness
Distributor
Alternator
Intake Manifold
Exhaust Manifold
Fuel Rail
Injectors
Throttle Body
All Bracket and Sensors
Air Conditioning Pump
Intermediate Shaft
Power Steering Pump
Axles
Linkage
Header
My '92 Civic IS equipped with VTEC (Si hatch), and for now I will be sticking with the stock integra/civic mounts. But Isn't it true that the JDM harness is meant to plug in on the opposite side of the car as compared to the USDM version? What happens with that? Do I splice into the Type R harness, and extend the wires so as to reach the other side of the car? And also, I hear that the plug ins on my stock P28 are completely different then the Type R plugs themselves..
Sorry if this is taking a little bit to sink in, but I'm doing my best to learn this stuff, and its pretty hard until I actually do it myself... thanks B18C5-EH2!
Thread Starter
Honda-Tech Member
Joined: Oct 2007
Posts: 78
Likes: 1
From: AB, Canada
Re: OBD2 and OBD1 questions (Creepsjr)
Ah, wait, I see it now... I realize how the Type R harness plugs into the existing civic chassis harness.. 
it all makes sense. But still, do I need to drag the harness plug to the other side of the car to make the connection between the chassis harness and engine harness?
Also, is there anyway to tell if my existing exhaust will bolt up to the ITR header??
it all makes sense. But still, do I need to drag the harness plug to the other side of the car to make the connection between the chassis harness and engine harness? Also, is there anyway to tell if my existing exhaust will bolt up to the ITR header??
Honda-Tech Member
Joined: Aug 2005
Posts: 5,130
Likes: 1
From: San Jose, CA, US
Re: OBD2 and OBD1 questions (B18C5-EH2)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by B18C5-EH2 »</TD></TR><TR><TD CLASS="quote">Bump?
What, no argument now? Come on bro I thought I was a retard or some ****?</TD></TR></TABLE>
sorry dude but i havnt been on h-t for a couple of days. different people have different ways of swapping in the 98+ motors into obd-1 cars. my way works for me. i probably misread the post that you posted but i think this guy is talking about a jdm itr
What, no argument now? Come on bro I thought I was a retard or some ****?</TD></TR></TABLE>
sorry dude but i havnt been on h-t for a couple of days. different people have different ways of swapping in the 98+ motors into obd-1 cars. my way works for me. i probably misread the post that you posted but i think this guy is talking about a jdm itr
Honda-Tech Member
Joined: Aug 2005
Posts: 5,130
Likes: 1
From: San Jose, CA, US
Re: OBD2 and OBD1 questions (Creepsjr)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Creepsjr »</TD></TR><TR><TD CLASS="quote">Ah, wait, I see it now... I realize how the Type R harness plugs into the existing civic chassis harness.. it all makes sense. But still, do I need to drag the harness plug to the other side of the car to make the connection between the chassis harness and engine harness?
Also, is there anyway to tell if my existing exhaust will bolt up to the ITR header??</TD></TR></TABLE>
you are gonna need a test pipe or a 2.5in cat to make the header fit to the exhaust. if you have the jdm itr it has a 2.5in collector
it all makes sense. But still, do I need to drag the harness plug to the other side of the car to make the connection between the chassis harness and engine harness? Also, is there anyway to tell if my existing exhaust will bolt up to the ITR header??</TD></TR></TABLE>
you are gonna need a test pipe or a 2.5in cat to make the header fit to the exhaust. if you have the jdm itr it has a 2.5in collector
Former Moderator
Joined: Oct 2001
Posts: 16,612
Likes: 55
From: Southside ATL, GA
Re: OBD2 and OBD1 questions (Creepsjr)
While I have actually seen a JDM ITR swap in a 1992-1995 hatch with the JDm harness stretched around to the wrong sides of the engine bay, I don't recommend it.
Stick with the USDM 96-01 Integra GS-R/Type R engine harness and it will be much cleaner and easier to install.
Just check the pics I posted and you'll see that the 96-01 engine harness plugs in at the shock towers, and then the P28 ECU will still plug in like normal under the dash at the passenger side floorboard.
Stick with the USDM 96-01 Integra GS-R/Type R engine harness and it will be much cleaner and easier to install.
Just check the pics I posted and you'll see that the 96-01 engine harness plugs in at the shock towers, and then the P28 ECU will still plug in like normal under the dash at the passenger side floorboard.
Thread
Thread Starter
Forum
Replies
Last Post
ek9eli
Honda Civic / Del Sol (1992 - 2000)
11
Feb 16, 2014 06:52 AM
