ALright so i have a 2000 honda civic ex 2 dr. I bought the car about a year ago with a swapped 97 honda civic lx motor. My problem is that i have the ex ecu in the vehicle, and my motor hits a rev limiter at 5200 rpm. I have asked around about this problem, and my response was to buy a conversion harness off xact dyno, and then purchase a 96 acura integra ls ecu. I have purchase this harness, but now that i am looking for ecu i noticed that the integra ls 96 ecu is obd2. so i am just wondering if my information is incorect, or if any one else has had this problem. Bottom line is that i just need to know the ecu that will be compatible with my harness motor and car, if i even need the harness. And by the way i have searched for a long time, since about last april, so dont tell me to use the search button.

 

If its an automatic get an automatic '99 - '00 CX/DX/LX (P2E) automatic ECU, plug it in, thats it. If its a manual get a manual '99 - '00 CX/DX/LX (P2E) ECU, preform the IACV fix, shown here in reverse



you will need to obtain a 3 wire IACV plug in this case and add a wire to the engine harness from the 3 wire IACV plug to pin B15 at the ECU.

 

dude a 97 civic motor will have an ECU of obd2
92-95 obd1
96+ is obd2
and the new models have obd2 can bus. or something like that.
correct me if im wrong

 

So what your basically saying is that the 2000 honda civic ex has a 2 wire iacv plug, and what i need to do is move b6 to b23 and take the un used wire from the new three wire plug and plug it into b15 to the ecu

 

because i do have a 2000 civic cx ecu, and when i did try to use that ecu, i would push the gas in just a little bit, and it was like i had 2 step. my car would hit a limiter at about 1500 rpms, and then with a little more gas i could go all the way to 7000. I tried driving it like that and it was so hesitant i could barley get moving.

 

Manual transmission EXs use the 2 wire IACV, automatics use a 3 wire IACV the same as all D16Y7s

Almost, move B23 to B6. Remember the diagram is for converting from a 3 wire to 2 wire IACV, you want to do the opposite.

 

right but he would need the harness because the motor and the car should be OBD2, however, this person may have been telling him to get the OBD2a to OBD2b conversion harness because 1996-1998 have OBD2a and the 1999-2000 have OBD2b...

but as 94eg8 says he can accomplish the same thing by following his instruction...

 

nobody noticed he said the car has an lx motor = no vtec?

 

DOH! i feel like a moron hahaha. Thanks for correcting though.

 

That was the first thing I noticed when I read the OP, which is why I told the OP to rewire the IACV fix and use a P2E ECU.

 

Alright so today i looked at my iacv to see if i had the three wire plug already. I dont. It looks like theres only two wires. So after i get this plug, will i also have to replace my iacv? and if i do, wont i have to replace my intake manifold because i beleive i have an ex intake manifold, and i read that the lx model and ex model differ slightly.

 

[QUOTE=v-tecnition;36700415]So after i get this plug, will i also have to replace my iacv?

Yeah, the whole throttlebody actually. The three wire IACV is on the throttlebody unlike the 2 wire version.

Ideally, but you can just block off the holes for the IACV on the back of the IM with piece of aluminum plate and a gasket, you could actually probably get away with just leaving the old IACV bolted to the IM and plug the coolant lines.

Its considerably more than a slight difference. Your ideal solution is probably to run an automatic Y8 IM and TB its setup the same way as a Y7 in terms of the IACV but otherwise its the same as a manual Y8 except the spot for the 2 wire IACV is blocked off.

Heres a picture that will hopefully explain some of it.

 

thanks for all of your help everybody, my car now goes to redline, and i am a much happier person.