kay_animation

I currently have a completely stock 1997 JDM ITR (b18c) engine in my 1996 EK hatch.

-: Pictures are from 2kgs-R's post. (see bottom of this post)

-: These are things that I have gathered from everywhere over the last view weeks.

-: I know that because my car is a 96-98, it must be obd2a, 99+ is obd2b, etc to be a legal swap for emissions purposes. I live in Maryland and do have emissions.

-: I am told that when you go to emissions with a 96+ car, nomatter what you have done to it, they will only do an obd2a or b or whatever test on it. Meaning they don't plug in the sniffer to monitor exhaust, they simply plug up a device into your ecu which retrieves your engines "logs" of emission data to see if you car is running right.

-: If you have a jdm ecu, nomatter what engine, you will fail as jdm ecu's will not talk to emissions computers in the us. They will not do a sniffer test (few exceptions for some lucky people) but law wise, they won't, you just FAIL. Even if your engine is putting out pure love from the exhaust.

-: I am aware of most of the things that I must do to convert it to an obd2a car.

-: Vtec sol must be replaced with a usdm itr sol. as the jdm one does not have an oil pressure switch. Without this, I believe vtec will not work when you install an obd2a ecu. You can wire it, but for simplicity, the whole vtec sol. was replaced. (I have done this)


-: An obd2a engine wire harness must be used, you can rewire a non obd2a one but for simplicity, just replace. (I have done this)

-: The sensor on the oil pump (crank sensor I believe) needs to be installed but will only bolt up to the usdm itr oil pump, so basicly, a usdm itr oil pump and sensor must be installed. Without this, you get a cel when you install a usdm itr ecu as the sensor is not there. (I have not done this)


?? When you guy the oil pump, is the sensor included from say ACURA or is it seperate? (but thats just a lazy question I just thought of, not the reason for this post)

-: An extra O2 sensor must be added somewhere after the cat and extended to the wire harness to become the secondary ecu. You can guess what happens when you install a true obd2a ecu without a second o2 sensor. CEL. (I have not done this)

NOW, THE TRUE QUESTION!!!

-: A usdm ITR ecu will be needed which is obd2a that will make everything above become used and will let you pass an obd2a emissions test. When they plug in assuming all parts are working and everything.

Now the question. The closest ecu there is to a jdm ecu thats obd2a is a usdm itr ecu, p73 I believe. The only thing thats wrong with this ecu is that jdm engines and itr engine are different compression wise. Meaning that thought they are the same engine, different gas/fuel mistures are pragrammed into them meaning that because a jdm engine has higher compression, a usdm itr ecu will make a jdm engine run closer to a lean mixture right.

For the sake of simplicity lets just throw out the octane thing between the us and japan as we are all in the us and 91-93 octane is the highest we'll see daily.

So if this is all true, a jdm itr engine on a usdm itr ecu will run lean (93 octane) because compression is higher and the usdm itr ecu right?

Now the bigger question. What is the best ecu to use on an obd2a car that must remain obd2a! Every person I ask always says P28 kenji (sp) but what they don't realize is that that ecu is great for OBD1 cars, but it makes my car illegal and defeats the purpose of all the mods to the engine to make it obd2a right? I also understand from a lot of searching and reading that forum dedicated to cracking the obd2a ecu that its very very hard and there is no chip that exists for an obd2a ecu right?

So back to the origional question, what obd2a sensor? The main purpose of this is that I wanted an ecu thats exactly identicle to the jdm itr ecu but is a true obd2a ecu and not japans special version of an obd2a ecu that only uses one o2 sensor? Sounds obd1 to me.

But I wanted to have it be a permanent solution and not a quick and dirty thing like just slapping a obd2a gsr ecu on for emissions day and then tossing it.

Swapping the cams to lower compression would make everything right but I want the higher compression as I am staying na so I actually like it. So no swapping heads with an usdm itr engine. That defeats the purpose of a jdm itr and I would be basicly converting to a c5 again.

So Ideally, in the end of the perfect world, I would have a jdm itr engine, still runing off the jdm itr fuel maps and compression, but converted to obd2a standards emission wise and actually working.

Search is the worse thing you can say as this is everything I have found in the last few weeks so I'm guessing an answer is too long gone to fine right now.

I found this post and it helped the most but I'm still missing some stuff:
https://honda-tech.com/zerothread?id=906684

kay_animation

Also, people in hard emissions states like california (mainly cause you guys had to do it perfect to pass) with my similar setup, 96+ obd2a car with a jdm itr engine who passed the obd2a test and have a car that feels the same or stronger after the conversion, please post "EXACTLY", what you did.

2lua

well you will need to get usdm itr ecu. add crank sensor and sprocket. your car should have 2 o2 sensors. and you are not live in a prefect world. you can't have a cake a eat it too. there is no other way around it buddy. welcome to world of hybrid.

kay_animation

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2lua &raquo;</TD></TR><TR><TD CLASS="quote">well you will need to get usdm itr ecu. add crank sensor. your car should have 2 o2 sensors. and you are not live in a prefect world. you can't have a cake a eat it too. there is no other way around it buddy. welcome to world of hybrid.</TD></TR></TABLE>

the one answer I was hoping was not final. Thanks. I guess engine health wise, would it be better to just switch to lower compression usdm itr pistons to lower compression so at least the engine won't be running lean?

klungemonger

I don't think the differences in compression are enough in the 96-98 ITR to make the USDM P73 inappropriate for your setup. I think it's the right choice.

As for harness, you MUST use a 96-98 harness, not because of emissions but because no other harness will fit & work on your car. All 96-00 Civic harnesses are 1-piece from motor to ecu, all Tegs and earlier Civics are 2-piece harnesses. And since the wiring scheme changed in 99-00 (an entire ecu plug taken from the engine harness and moved to the cabin harness) OBD2B harnesses don't work either. For a minimum of wiring mods use one from an EX 5-speed model. The thing is, the secondary O2 sensor (critical to passing emissions!) is not in that harness. Here's some mods you will have to do:

1) Change 3-wire CKP/CKF plug to 2-wire plug. Just ignore the extra wire
2) The P73 has an immobilizer circuit that disables the fuel pump, I *think* you can override that by moving the fuel pump signal from pin A16 to pin A15. Search around, there's a how-to I read before on this...
3) Pull your secondary O2 sensor wiring out of your stock harness and replace it into the same pin locations on the EX harness. You can run the wires/plug under the carpet to the hole in front of the shifter where the O2 sensor would be in the EX, right above the converter.
4) Lengthen some branches to reach where they need to go.

That's all I can think of for now, anyone else?

2lua

well you other mean of tuning, like vafc, adjustable fpr...ect

imo just get a usdm ecu go get it inspected then swap the ecu over afterward. you be done about 5 min max. then go enjoy your car. gl

kay_animation

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 2lua &raquo;</TD></TR><TR><TD CLASS="quote">well you other mean of tuning, like vafc, adjustable fpr...ect

imo just get a usdm ecu go get it inspected then swap the ecu over afterward. you be done about 5 min max. then go enjoy your car. gl</TD></TR></TABLE>

very true. I guess I'll be another person just slamming the car inspection day so that I'm too low to get in and just getting the wavers

hj2

kay animation

sorry to hack your thread but I wanted to ask you something
are you sure 96+ cars don't get attached to the "sniffer"?
they just connect to your ecu??

i have a usdm 2000 gsr swap in my 96 cx hatch, and getting it legal is a biz. not being attached to the sniffer would make it so much easier to get it legal

thanks