obd1 / obd2 question
01-11-2005, 09:45 AM
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obd1 / obd2 question
i'm thinking of doing a gsr swap into an eg, so i've been doing a lot of reading on the swap and the obd stuff. just wanted to double check that i have it straight...
you only need a wire harness when you put a obd1 engine in an obd2 car correct? if you put a obd2 engine in a obd1 car (like a newer gsr engine in an eg) you can just plug right in and it will be backwardly compatible with obd1. in this case tho you would still need a obd1 ecu correct? so you couldnt use the ecu from the obd2 engine that you were dropping in the car unless you updated the entire car to obd2 which i'm guessing is a huge pain in the ***.
also is there a major difference between using an obd2a or obd2b engine in a obd1 car?
sorry if this is a dumb question... just a little confused about this stuff and wanted to clarify it. thx.
you only need a wire harness when you put a obd1 engine in an obd2 car correct? if you put a obd2 engine in a obd1 car (like a newer gsr engine in an eg) you can just plug right in and it will be backwardly compatible with obd1. in this case tho you would still need a obd1 ecu correct? so you couldnt use the ecu from the obd2 engine that you were dropping in the car unless you updated the entire car to obd2 which i'm guessing is a huge pain in the ***.
also is there a major difference between using an obd2a or obd2b engine in a obd1 car?
sorry if this is a dumb question... just a little confused about this stuff and wanted to clarify it. thx.
01-12-2005, 05:24 AM
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Re: obd1 / obd2 question (Paulnsx)
anyone know? mainly i just wanna know what i would need to put an obd2 motor in an eg... from what i've read i thought u could just plug it in as long as u use a obd1 ecu.
01-12-2005, 10:41 AM
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Re: obd1 / obd2 question (smart monkey)
Well damn I thought if you had:
OBD-1 car w/ OBD-2 Engine
You Needed:
One of those harness adapters that hook the car harness to the OBD-2 ECU.
and Vice Versa if you had an OBD-2 car w/ and OBD-1 Engine.
Learn something new everyday...!
How does all that work? How does an OBD-1 ECU diagnose an OBD-2 engine? Doesn't OBD-2 have more codes and shiznit?
OBD-1 car w/ OBD-2 Engine
You Needed:
One of those harness adapters that hook the car harness to the OBD-2 ECU.
and Vice Versa if you had an OBD-2 car w/ and OBD-1 Engine.
Learn something new everyday...!
How does all that work? How does an OBD-1 ECU diagnose an OBD-2 engine? Doesn't OBD-2 have more codes and shiznit?
01-12-2005, 11:18 AM
#5
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Re: obd1 / obd2 question (Paulnsx)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Paulnsx »</TD></TR><TR><TD CLASS="quote">you only need a wire harness when you put a obd1 engine in an obd2 car correct? if you put a obd2 engine in a obd1 car (like a newer gsr engine in an eg) you can just plug right in and it will be backwardly compatible with obd1.</TD></TR></TABLE>
This is correct only if you use an OBD2 INTEGRA engine harness and not an obd2 civic harness, in the OBD1 vehicle. OBD2 integra engine harnesses are backwards compatible with OBD1 vehicles because of their 2-piece design. OBD2 civic harnesses are not back/compatible because of their 1-piece design.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Paulnsx »</TD></TR><TR><TD CLASS="quote">
in this case tho you would still need a obd1 ecu correct? so you couldnt use the ecu from the obd2 engine that you were dropping in the car unless you updated the entire car to obd2 which i'm guessing is a huge pain in the ***.</TD></TR></TABLE>
That is correct. You can stick with using an OBD1 ecu (P72 in this case), to power your OBD2 GSR engine and it will run perfectly fine. Now if you wanted to run an OBD2 ecu, you'd have to buy an OBD1->OBD2a or obd2b jumper harness; and depending on if you would be using an a US or JDM OBD2 ecu - this would matter as US OBD2 ecu's look for additional sensors that you would need to wire in manually (2nd 02 & CKF sensors mainly). BTW, I sell this jumper if you check out my ecu site.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Paulnsx »</TD></TR><TR><TD CLASS="quote">
also is there a major difference between using an obd2a or obd2b engine in a obd1 car? sorry if this is a dumb question... just a little confused about this stuff and wanted to clarify it. thx. </TD></TR></TABLE>
No there isn't HP wise. Only real difference is that you'll usually find lower mileage on OBD2b engines.
This is correct only if you use an OBD2 INTEGRA engine harness and not an obd2 civic harness, in the OBD1 vehicle. OBD2 integra engine harnesses are backwards compatible with OBD1 vehicles because of their 2-piece design. OBD2 civic harnesses are not back/compatible because of their 1-piece design.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Paulnsx »</TD></TR><TR><TD CLASS="quote">
in this case tho you would still need a obd1 ecu correct? so you couldnt use the ecu from the obd2 engine that you were dropping in the car unless you updated the entire car to obd2 which i'm guessing is a huge pain in the ***.</TD></TR></TABLE>
That is correct. You can stick with using an OBD1 ecu (P72 in this case), to power your OBD2 GSR engine and it will run perfectly fine. Now if you wanted to run an OBD2 ecu, you'd have to buy an OBD1->OBD2a or obd2b jumper harness; and depending on if you would be using an a US or JDM OBD2 ecu - this would matter as US OBD2 ecu's look for additional sensors that you would need to wire in manually (2nd 02 & CKF sensors mainly). BTW, I sell this jumper if you check out my ecu site.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Paulnsx »</TD></TR><TR><TD CLASS="quote">
also is there a major difference between using an obd2a or obd2b engine in a obd1 car? sorry if this is a dumb question... just a little confused about this stuff and wanted to clarify it. thx.
</TD></TR></TABLE>No there isn't HP wise. Only real difference is that you'll usually find lower mileage on OBD2b engines.
01-12-2005, 01:03 PM
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Re: obd1 / obd2 question (K@man)
very informative and greatly appriciated that cleared up pretty much all the questions i had.
i should be picking up a 94 si hatch this spring. after that i'll be looking for an engine to drop in and if i go odb2 with the engine and ecu i'll def send u a pm. is there any disadvantage to using a obd1 ecu with an obd2 engine? if not i'll just go with what i find easiest and cheapest.
that cleared up pretty much all the questions i had.i should be picking up a 94 si hatch this spring. after that i'll be looking for an engine to drop in and if i go odb2 with the engine and ecu i'll def send u a pm. is there any disadvantage to using a obd1 ecu with an obd2 engine? if not i'll just go with what i find easiest and cheapest.
01-12-2005, 01:09 PM
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Re: obd1 / obd2 question (Paulnsx)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Paulnsx »</TD></TR><TR><TD CLASS="quote">very informative and greatly appriciated that cleared up pretty much all the questions i had.
i should be picking up a 94 si hatch this spring. after that i'll be looking for an engine to drop in and if i go odb2 with the engine and ecu i'll def send u a pm. is there any disadvantage to using a obd1 ecu with an obd2 engine? if not i'll just go with what i find easiest and cheapest.</TD></TR></TABLE>
No disadvantages at all, in fact I suggest running an OBD1 ecu over an OBD2 ecu any day, because you can upgrade/chip an OBD1 ecu way easier than you can vs. an OBD2 ecu. Only real disadvantage is if you wanna make your car smog legal and you go visit a Refferee. They'll more than likely fail you 'cuz you'd be running an OBD1 ecu with an OBD2 engine, when you should be using the ecu that matches the same year as the engine you'd be using. That's all moot if smogging isn't your priority tho.
good luck next spring..
that cleared up pretty much all the questions i had.i should be picking up a 94 si hatch this spring. after that i'll be looking for an engine to drop in and if i go odb2 with the engine and ecu i'll def send u a pm. is there any disadvantage to using a obd1 ecu with an obd2 engine? if not i'll just go with what i find easiest and cheapest.</TD></TR></TABLE>
No disadvantages at all, in fact I suggest running an OBD1 ecu over an OBD2 ecu any day, because you can upgrade/chip an OBD1 ecu way easier than you can vs. an OBD2 ecu. Only real disadvantage is if you wanna make your car smog legal and you go visit a Refferee. They'll more than likely fail you 'cuz you'd be running an OBD1 ecu with an OBD2 engine, when you should be using the ecu that matches the same year as the engine you'd be using. That's all moot if smogging isn't your priority tho.
good luck next spring..
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