12three

hey guys.. i'm pretty sure this topic has already be discussed but i tried searching already.. anyways please help point me in the right direction..

i recently swapped a k engine into my 99 civic si.. which left me the complete complete b16a2 engine swap.. My original plans was just to sell it but i found a great deal on a 1996 civic hatch cx shell.. so i end picking it up..

my problem lye's with the engine harness' .. it doesn't plug and play.. due to different obd's
i thought all i had to do was buy a jumper harness so i bought one from rywire and turns out i need more then just the jumper harness..

can someone explain what else i need to get?

i'm trying to run the stock engine harness and ecu from the motor.. is it possible? or am i going to need to buy a d-series obd2b engine harness?.. if this makes any sense.. again the shell is a 96 civic..

Arthas

You can wire up the VTEC with the CX harness but its gunna be tricky and a lot of work. You will need to move pins around on the ECU harness itself, and run a few custom VTEC wires.

You said you swapped a K which probably left you with a spare B16A2 harness. Use that, and make the car OBD2B.

12three

yes i have a spare obd2b engine harness from the engine i didn't use when i did the swap.. by the end of the harness where it plugs into the ecu.. it doesn't all clip.. if you understand what i mean..

how would i make the whole car obd2b?

Arthas

Of course its not gunna plug into the ECU if thats what youre asking. Youll need to use your factory B16A2 ECU, which is P2T I believe.

12three

ok... this is what i have.. i have complete 99 civic b16a2 engine.. its complete.. b16a2 motor, the b16a2 engine harness, with the b16a2 ecu... i don't not have the cx wiring harness..

due to the car being a obd2a and the motor being a obd2b there must be more to it..

i thought that all i would need is a jumper harness and it would be plug and play.. but it turns there's more to the swap then the just the jumper harness to get the car running..

Arthas

No. Jumper harness is just to convert from OBD2 to OBD1. It doesnt give the car the proper VTEC plugs and wires.


Remove D16Y7 and CX harness. Install Si harness and B16A2. Enjoy a beer.

12three

when you say si harness you don't mean the engine harness do you..? do you mean the car harness correct?

12three

does this sound correct?.. instead of using my b16a2 engine harness i need to find a "obd2a" which is from a 96 to 98 civic ex engine harness and run with that one and use a jumper harness from obd2a to obd2b ecu..

the reason for switching over engine harness is because the one of the car clips does not fit into the ecu therefore you have to run with a obd2a engine harness... and probably have to modify a little here and there..

or am i making this more complicating than it really is..

ken9

You brought a jumper harness and it didn't work? You might have brought the wrong one. It's possible you can frun the stock engine harness but i think you might need a jumper wire. I wouldn't cut any of the wire because to much work and does make it look neat, unless you know stuff about electrical. Doing a b-series swap need more than harness wire.. YOu might need an engine mount, b series shifter and etc..

94EG8

If you are using a '99 - '00 Engine harness you will need a '99 - '00 Cabin harness as well, you can use one from a coupe or hatch, doesn't matter, but don't use one from an HX coupe (they stayed OBD2A all the way through production) If you plan on putting in power windows or locks in the future now is a great time to get an EX/Si cabin harness.

12three

as far as engine mounts, b series shifter and ect.. the motors already in the car an everything's hooked up.. ready to go.. just ran into the problem where the plugs by the ecu all didn't hook up..

thought all i need was a jumper harness so bought a obd2a to obd2b ecu jumper harness..

called the place i bought the jumper harness from and he said i'm going to need a 96 to 98 ex engine harness along with the jumper harness i purchased from him..

this is going to be my winter beater.. i just want to get it up and running asap without spending anymore money..

94EG8

Its going to involve pulling apart the vast majority of the interior. Its not so much hard or difficult as it is time consuming. However, remember this, if you get an OBD2A engine harness you will need a conversion harness to use your ECU (or alternatively get an OBD2A P30) as well as the fact that you will need to make some modifications to the engine harness. If it was me i'd just replace the cabin harness.

12three

ok.. thanks.. a little more trouble than i was hoping for.. but too late to turn around now..

mckenze44

iTrader: (3)

u could buy a 0b2a engine harness...96-98 ex manual harness. thats what am useing in my car...i thought a 99-00 od2b would work but did not. with the 96-98 ex manual harness it will plug up easily

12three

i think this is what i will end up doing.. i hope it doesn't involve too much rewiring of any sort..

mckenze44

iTrader: (3)

Nope, u don't have to rewire nothin....it plug up to the motor like it's was made for the motor....but the thing with the engine harness is it's hard to find. I bin look for it for a while and saw it in eBay and paid a good bit if change but it was worth it... Makes the engine bay looks clean instead of all kind of wires crossin over each other and also easier to swap the engine... But get the obd2a engine harness from a 96-98 ex manual not auto. That's the best way to go

12three

thanks for the info... Did you run a jumper harness to the stock motor ecu also? I don't want to forgetting anything.

You didn't hafta run a secondary o2 sensor did you? No check engine or anything??

94EG8

You will need to run an OBD2A to OBD2B jumper harness to run your ECU. (or alternatively get an OBD2A P30

If you are running a USDM OBD2 ECU you will have to wire in the seconday O2 sensor when using a Y8 harness. EX civics had the seconday O2 sensor wiring integrated into the cabin harness, CX/DX/LX did not. If you use a Y7 harness it will have the secondary O2 sensor wiring already but it will require several other modifications.

12three

I actually bought the obd2a to obd2b jumper harness thinking this is all I needed.. So I have the jumper harness already..

Since I alrdy have the jumper harness and ecu I think the easist way to go about it is to go find a y8 engine harness and tap in the sencondary o2..

This should be all that has to be done?? Correct me if I'm wrong.

94EG8

Thats pretty much it, secondary O2 sensor wiring will have to run right back to the ECU.

mckenze44

iTrader: (3)

well am useing a 0bd1 p30 ecu so it will not have a check engine light for the secondary o2 sensor...i had to but a 0bd2a to obd1 jumper harness to use that ecu...i have no check engine light...like the guy say above if u use a obd2a ecu it will give u a check engine light for the secondary o2 sensor and u will have to do some modification...most people use obd1 ecu...its up to u if u want to use a ob2a, obd1 or obd2b ecu

HondacivDX

swaped my 99 b16a2 in a 98 honda civic best bet is to find a obd2a harness and buy a jumper harness obd2a to obd2b you cant use the si harness in a 96-98 civc cuz the plug ends are different between 96 to 98 and the 99-00 harness

12three

wow.. i didn't no it would be so hard to find a y8 engine harness.. its like no one has one for sale..

94EG8

High demand and low supply.

Tmklim

Not to hijack his thread or anything but I have a similar question that's the exact opposite at the same time.I have a 97 dx hatch w a y8 auto intake which I plan on converting to d16z6 itb(just for the he'll of it).so in doing this I bought a friends kenji tuned p28 that she got for her em1.I plan on staying non vtec in which imposes my problem.all ink owns it says b16,msd,intake,5200 vtec 9000 Redline.it came with an obd2b to obd1 jumper.when I get my obd2a to obd1 harness how do I keep the ecu from looking for vtec?or do I need to wire in a vtec solenoid then paperclip the harness to create a bridge to take it out of limp mode?