freebyrd

I am doing my first swap and learning alot along the way. Ive found a lot of valuable info and answers to my questions on this site, but i cant specifically find my motor/ecu/chasis combo.

I have a 2000 integra GS sedan. stock b18b manual trans. (OBD2b)

im going to a 1999 JDM b18c (GSR) with matching trans, and P72 ECU(OBD2a)

1) do i need to use my LS engine harness? it came with the jdm harness but i dont think it will work, correct?

2)if i use the JDM P72, do i need the jumper harness OBD2b->OBD2a in order to run it?

3)would you guys recommend rywire or similar vtec harness?

4) will my b18b "A pipe" fit on the b18c exhaust manifold, or should i swap the whole manifold over?

freebyrd

Bump. I'll swap the manifolds..ordered the jumper but I need more info on using the LS engine harness...anyone done this?

Eg.ls.turbo

A ls engine harness will work. Just wire in vtec, vtec pressure switch and Iab if ur using stock gsr manni, but ur using aftermarket manni then don't worry about the Iab.

jdm201010

Eg.ls.turbo is correct the ls harness will work. I'm running a 97 ls harness on my 01 gsr. Don't forget to wire the in the v tec like mentioned.

Eg.ls.turbo

Also forgot to mention if ur using a single runner manni or aftermarket make sure u chip ur p72 ecu for it, if u don't chip it then the ecu will look for the Iab and throw a cel. Causing some major power loss.

freebyrd

OK thanks. I opted to purchase a 97 GSR harness and got a VTEC subarness from rywire, I also got the ecu obd2b to obd2a jumper. I think everything should be plug and play now. I did have to swap the entire exhaust manifold over from my LS to the new GSR because it is different. The A-pipes are different as well and won't interchange. Anything else I should worry about?

BTW the LS harness on the GSR motor wasn't a plug and play deal...some plugs were way to short and had a round plug where I needed a square plug and vice versa. It may be the difference between obd2a and obd2b I'm not sure did any of you have to extend and swap out plugs? Or just plug and play?

HondaPartsHero

The OBD2 P72 is not "chippable" only the OBD1 version. The IAB's will not throw a check engine light but you will lose some low end torque if you keep the P72 and IAB's and don't wire them in.

Post pics of the plugs that don't match because off the top of my head there shouldn't be too many that don't match up. Also the JDM B18 won't have the CKF sensor by the crank so you can either bypass it (google Bypass CKF) or swap over the oil pump from your LS engine. The JDM engine won't have an EVAP purge either so you'll have to swap that over from your LS somehow or you're going to throw a check engine light if you're using a USDM ECU. The OBD2 JDM B18 won't have a VTEC pressure switch so you'll have to bypass that or buy one and if the solenoid has a port screw it in but the JDM P72 won't throw a code for it. Also note if you have emissions testing in your area that uses the OBD2 port scan the JDM ECU won't pass emissions.

freebyrd

Thank you for that helpful information. I won't post pictures because I've sold the LS engine already. Will I need to bypass the CKF if I'm running the JDM p72 and the obd2b to 2a jumper? Or just tie wrap the plug on the usdm harness out of the way?

Do I need evap purge or VTEC pressure switch if I plan on running the JDM p72?

Lucky for me I have no emission testing in my area of any kind.

HondaPartsHero

Yeah JDM ecu takes care of all that, no 2nd 02, evap or ckf