is it possible to convert to obd1 from obd0? if i want to us a 92ls ecu in my 90ls can i get a wiring harness to convert?
Re: how can i convert from OBD0 to OBD 1?
Originally posted by ZeroMR
is it possible to convert to obd1 from obd0? if i want to us a 92ls ecu in my 90ls can i get a wiring harness to convert?
It sure is possible, i’ve done it to many CRX’s… it just takes alot of time and patience… i know there was someone selling jumpers before for this but they stopped because too much additional wiring had to be done… just to give you an idea of what needs to be done, you gotta get the ecu clips with some wire still attached, an OBD-1 distributer and wiring if you want to use grey plugs, the 4-wire O2 sensors, and not sure on DA’s but on CRX’s you gotta get a VSS and wire that up… hope this helps :bang:
you will only need one 4 wire o2 sensor. Also the wiring is just time consuming, if you have the wiring diagrams for both obd0 and obd1 ecu’s its pretty straitforward. You will also possible need either a new manifold or modify your existing manifold since you will only need one o2 sensor- you can always just leave the other o2 sensor just sitting ther not plugged in though
the conversion is very straightforward if you use a jumper harness. I bought an obd0 to obd1 jumper harness from turbo_ek@yahoo.com It was $160 shipped. I’m very happy with it.
do a search for posts by me and use some key words…i’ve gone over the conversion to a good amount of detail in some other posts. They are fairly recent so it shouldn’t be too hard to find.
i’d also like to ask why you want to convert? You want to use a 92LS ecu opposed to your 91 ecu? Why? One ecu is no better than the other. If you want the 92 one cause its already been chipped then its a waste of $$ to convert. It’d cost you more $$ in parts and time than it would to just get your other ecu chipped. Really there are few reasons to convert.
91integraga: i think the benefits of an obd1 conversion rely more along the lines of being able to use an obd1 distributor- there are about 40% more teeth on an obd1 distributor as compared to an obd0- this means that the ignition and ecu “talk” to each other 40% more often and will respond 40% quicker to a disturbance be it by accessories draining voltage and affecting you idle to pedal responiveness and fuel consumption. Also these benefits are exponential when a hondata setup is put on an obd1 equipped honda. this along with the fact that an obd1 ecu is an 8 bit while an obd1 ecu is a 32 bit- its literally the difference between an OG nintendo and a super nintendo- I’m sure that analogy will hit home for most of us older gen Xers 
Originally posted by gen2ls/vtec
[B]91integraga: i think the benefits of an obd1 conversion rely more along the lines of being able to use an obd1 distributor- there are about 40% more teeth on an obd1 distributor as compared to an obd0- this means that the ignition and ecu “talk” to each other 40% more often and will respond 40% quicker to a disturbance be it by accessories draining voltage and affecting you idle to pedal responiveness and fuel consumption. Also these benefits are exponential when a hondata setup is put on an obd1 equipped honda. this along with the fact that an obd1 ecu is an 8 bit while an obd1 ecu is a 32 bit- its literally the difference between an OG nintendo and a super nintendo- I’m sure that analogy will hit home for most of us older gen Xers
[/B]
hehe, i was wondering when you’d chime in with that response. Don’t worry, i’ve read it each time you’ve posted it before, and i understand it and i realize the benefits. But seriously, is it that beneficial to most people? The answer is No. The cost of getting the harness, buying the extra wires, getting a distributor, getting the O2 sensor… for most people on a modest setup this is not going to be a cost efficient modification.
I totally understand that it is a better system (although for normal driving conditions or on a car that isn’t heavily modded i see no real worthwhile benefit of having it), and the Hondata factor is great. However until you or someone else can show me some proof of it being a cost effective mod (whether it adds power, aids in fuel economy…any substantial benefit) for someone running a less than very built motor I am going to continue to recommend that people spend their money elsewhere. There are way too many people out there running awesome obd0 setups for me to acknowledge any huge difference in performance betweenthe two systems.
oh, and i realize that what i just typed might sound a little combative…but really its not. You know me, i’m not like that. I’m curious to see what you have to say about the benefits of the obd1 system on cars that aren’t heavily modded.
No harm dood I dont take offense with someone disaggreement 
I think that in general, the car simply runs better no matter how modified it is. Another point to mention is if you’re in a major city that has strict emission laws, the odds of passing testing with a modified honda motor with an OBD1 setup is MUCH greater than with an OBD1 setup. Take for example the last time I “legally” smogged my car ( ) I more than double every test. However another ls/vtec done by carchitect ( my mechanic) was a 92 with p72 ecu and a test pipe and it passed no problems. Normally I’m against using specific examples for somethin like this but this is something I’ve come in contact with personally so I think it is valid. Also, I sincerely believe this is one of the reasons for the 10hp gain between the 90-91 and the 92-93 ls DA’s. I have no proof of this, just a belief. Other than that, the post I mentioned above concerning the distributor and the bitrate of the ECU’s simply make sense that fuel economy, responsiveness, and power would be affected.
Originally posted by gen2ls/vtec
[B]No harm dood I dont take offense with someone disaggreement
I think that in general, the car simply runs better no matter how modified it is. Another point to mention is if you’re in a major city that has strict emission laws, the odds of passing testing with a modified honda motor with an OBD1 setup is MUCH greater than with an OBD1 setup. Take for example the last time I “legally” smogged my car ( 
) I more than double every test. However another ls/vtec done by carchitect ( my mechanic) was a 92 with p72 ecu and a test pipe and it passed no problems. Normally I’m against using specific examples for somethin like this but this is something I’ve come in contact with personally so I think it is valid. Also, I sincerely believe this is one of the reasons for the 10hp gain between the 90-91 and the 92-93 ls DA’s. I have no proof of this, just a belief. Other than that, the post I mentioned above concerning the distributor and the bitrate of the ECU’s simply make sense that fuel economy, responsiveness, and power would be affected.
[/B]
well, i’ve had both setups now (eventhough i still need to get my new setup finalized), and thusfar i’ve seen no difference in the two. I’ve also had friends with both setups, gas mileage and just about everything else seem to be identical. I don’t mean to distrust you…but honestly i’m not going to put much weight on the thing you mentioned about smog. I’m pretty sure that could have numerous things that affect it.
The hp gain could be in part from the change to obd1, however i think its too well documented that the cams and exhaust manifold play a large role.
I know i don’t have enough experience with specific different systems to really be able to say that it does nothing, or very minimal. But from everything i’ve heard, seen, read, and witnessed the difference is not something i’d be willing to spend the $$ on. IMO money would be much better spent elsewhere.
Keep me posted if you ever get any other info on this, cause really i’d like to learn as much as possible.
well after the new drivetrain goes in that will be the next step to tackle. Already purchased the distributor ($75), ECU (free sorta), and obd1 plugs. Found a lightly used OEM O2 sensor and just debating what to do with the manifold issue. I’ll definately keep all posted on the subject, punn intended
Originally posted by 91IntegGS
[B]hehe, i was wondering when you’d chime in with that response. Don’t worry, i’ve read it each time you’ve posted it before, and i understand it and i realize the benefits. But seriously, is it that beneficial to most people? The answer is No. The cost of getting the harness, buying the extra wires, getting a distributor, getting the O2 sensor… for most people on a modest setup this is not going to be a cost efficient modification.
I totally understand that it is a better system (although for normal driving conditions or on a car that isn’t heavily modded i see no real worthwhile benefit of having it), and the Hondata factor is great. However until you or someone else can show me some proof of it being a cost effective mod (whether it adds power, aids in fuel economy…any substantial benefit) for someone running a less than very built motor I am going to continue to recommend that people spend their money elsewhere. There are way too many people out there running awesome obd0 setups for me to acknowledge any huge difference in performance betweenthe two systems.
oh, and i realize that what i just typed might sound a little combative…but really its not. You know me, i’m not like that. I’m curious to see what you have to say about the benefits of the obd1 system on cars that aren’t heavily modded. [/B]
well the reason i was asking is because my motor is almost completly built just waiting on the head to be finished then im going to turbo it. i need to get a engine management but Hondata or AEM ems is offered for us obd0 guys thats why.
Originally posted by ZeroMR
well the reason i was asking is because my motor is almost completly built just waiting on the head to be finished then im going to turbo it. i need to get a engine management but Hondata or AEM ems is offered for us obd0 guys thats why.
that is definitely a good reason to convert. but a lot of guys come on here and ask if they can convert simply because they already have an obd1 dist and ecu and don’t want to go buy the obd0 parts.