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98 honda civic LX
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Discussion Starter #1
im in the process of buying a d15b, i have a 98 honda civic 4 door. its obd2a all stock motor cept for a couple swaped items. i would like some input on how easy/hard it would/will be on swaping from obd2 to obd1? ill have the complete motor and trans im getting from a member on here, its basicaly a complete motor aside from being in the car already! engine harness, trans, ecu yadda yadda yadda. would it be worth the headache me doing it or just paying a shop and having them deal with it?

now i know what im doing but im not all that seasoned on swaps. this will be my first.
pretty decent at trouble shooting and i always double/tripple check everything.

input here-----V

and rep for the input given, good or bad
 

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It's gonna be fairly easy, i'm pretty sure the engine bay plugs are the same except the injectors and the dizzy (you can get a dizzy jumper harness thing). Then you'll need an OBD2A-OBD1 ECU jumper and I think that's about it. If it's vtec then you'll need to find some vtak sol/pres switch plugs and run them to the cabin and hook em up to the ecu jumper (which most likely has vtak wires on it).
 

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98 honda civic LX
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Discussion Starter #4
yeah its stage3 mad tytte vetc yo



seriously yes its vtec and its got a complete harness
 

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A RHD engine harness probably will not work in a LHD car without serious modifications.

Difficulty is dependent on which engine harness is in your car currently.

Connectors that are not the same as OBD1:
IAT
Injectors
Distributor
Alternator(not that it matters unless you fell compelled to switch to an OBD1 or OBD0 alternator for some silly reason)
EVAP Purge.
IACV for a Y7(3 wire on a Y7 versus 2 wire on all OBD1/OBD0 Civic/Integra)
Distributor(depending on which head casting, you may be able to keep your Y series Distributor. There are no electrical differences between OBD0, OBD1, and OD2A/B)

You will have to reroute some of the wiring if going form Y7 fail to anything else with a standard plenum style intake.

This is from memory, so I may have forgot something.
 

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98 honda civic LX
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Discussion Starter #6
i was told that i could use the y7 injectors? or maby it was i could use the y7 injector plugs?....like i said this stuff is new to me but im sure when i start to get into it, it will all finde its place.
 

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It's gonna be fairly easy, i'm pretty sure the engine bay plugs are the same except the injectors and the dizzy (you can get a dizzy jumper harness thing). Then you'll need an OBD2A-OBD1 ECU jumper and I think that's about it. If it's vtec then you'll need to find some vtak sol/pres switch plugs and run them to the cabin and hook em up to the ecu jumper (which most likely has vtak wires on it).
^this is true but you forgot to add the alternator,if the new motor is obd-1 ,you can switch from old motor tho..


A RHD engine harness probably will not work in a LHD car without serious modifications.

Difficulty is dependent on which engine harness is in your car currently.

Connectors that are not the same as OBD1:
IAT
Injectors
Distributor
Alternator(not that it matters unless you fell compelled to switch to an OBD1 or OBD0 alternator for some silly reason)
EVAP Purge.
IACV for a Y7(3 wire on a Y7 versus 2 wire on all OBD1/OBD0 Civic/Integra)
Distributor(depending on which head casting, you may be able to keep your Y series Distributor. There are no electrical differences between OBD0, OBD1, and OD2A/B)

You will have to reroute some of the wiring if going form Y7 fail to anything else with a standard plenum style intake.

This is from memory, so I may have forgot something.
rhd will not work with out without serious modifications.
 

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98 honda civic LX
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Discussion Starter #11 (Edited)
well then what about the o2 sensors?

my y7 has 2 o2 sensors

d15b has 1.

i don't really want to jimmy rig my motor obviously! i want it to last and last and and do it the right way the first time not hafta worry about cel's or anything like that.

i figure the best solution would be the jumper harness. and wadda ya know?, i already got the hook ups on those 2 things!
 

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OBD1 only uses the primary HO2S for closed loop feedback.

So, if you are truly converting to OBD1, using an OBD1 ECU, then don't worry about the post cat HO2S.

IIRC, the OBD2 EVAP Purge solenoid is inverted in it's operation compared to OBD1. ie, one is NO and the other is NC, but I could be wrong. I don't have one of each to compare at the moment.
 

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well then what about the o2 sensors?

my y7 has 2 o2 sensors

d15b has 1.

i don't really want to jimmy rig my motor obviously! i want it to last and last and and do it the right way the first time not hafta worry about cel's or anything like that.

i figure the best solution would be the jumper harness. and wadda ya know?, i already got the hook ups on those 2 things!
your gonna have to add the 2nd o2 sensor at some point to pass Emissions..but if your using a p28 ecu you only need the one o2 sensor
 

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if i run po8 ecu then i shouldn't have to worry if i get a jumper harness right!
You have to use an obd2 ecu only to pass emission other then that you can use a p28,po6 or the po8 ecu
 

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98 honda civic LX
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Discussion Starter #18
it comes with sk2 intake mani.....yeah i know ill miss my y8......and a greddy header. so ill go with whats on the engine just upgrade the cam get a cam gear..or not "chris" lol.....do the seals and run.....this is ofcourse i get it in the car...lol

if i got obd2 with that motor i think ill throw codes. the y7 as you know has 2 o2 the d15 has 1 pluse i think some of teh plugs are2 pin and not 3. which is no problem but i think alot of the issues ill run in to will probably come from the ecu and getting the chip re-burnt and the basic set up of teh ecu's for legality of emissions
 

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why not stay obd2 with that jdm D15b? I was going to do this before I found my gsr long block.

You can use your obd2 dizzy that you have. You can still run a y8 intake manfold and run obd2 fuel injectors.

ever thought about that?
So basically convert it to a Y8?
 

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So basically convert it to a Y8?
I'm curious what Pata is talking about too. The OBD1 D15b should run fine, if not optimal on a P28 with the stock maps. On the other hand, I find it hard to believe it's going to run anywhere near optimal if it's hooked to a P2P ECU. Aside from the differences in base timing, the Y8 maps have different timing due to the differences in the cylinder heads. I'll be interested in seeing if you can run your engine with a OBD2 ECU without a code.
 
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