I have a JDM engine but I do not have the ECU, but I am about to buy a JDM ECU but it does not come with the Wiring harness. I was wondering if the wiring harness from the American ECU will work with the JDM ECU if I just don't hook up the unneccisary stuff.

If your JDM engine is a regular SR20DE and not a VVL or DET, you could just use your USDM ECU.

I am using the USDM ECU but I want to use the JDM intake manifold to eliminate emmissions. Won't that require a JDM ECU?

I believe everyone here with a JDM engine is running the USDM ecu. I dont belive it will throw any codes on the USDM ecu, but you might wanna try posting this in the general sr20de forum, just in case no one here can answer your questions. There are a lot more Classic's with JDM's than NX's.

Running a JDM motor with a USDM ECU is fine. It won't throw any codes. I was running the JDM intake manifold too on mine with the USDM ECU, thus I had no EGR or AIV and it was fine, no codes.

Originally posted by MadNX
I am using the USDM ECU but I want to use the JDM intake manifold to eliminate emmissions. Won't that require a JDM ECU?

No, it won't on a Non-California ECU, but it probably will on a California ECU only reason being is because of the EGT sensor on the intake manifold, you don't have to worry about the EGR & AIV solinoids because they are not sensors they simply just let air pass through them are not by a signal from the ECU and as long as it is still pluged in you won't throw a code and the ECU won't know if you have the vacumm line hooked up, the only noticable sign will be your emmissions go higher.

NOTE: But still on a California car you can do 1 of 2 things for the EGT sensor so you wont throw a code, 1) wire in a resistor of the correct value, 2) or just relocate the EGT sensor somewhere in the exhaust track.

Just curious, why do you wnat to switch back to a JDM manifold?

I want to go back to the JDM manifold because my car is running poorly at idle and is sluggish inbetween 2000 and 3000 RPM and all the problems I have heard of has been with the emmissions. Why do you think I shouldn't go back to the JDM?:confused:

I want to go back to the JDM manifold because my car is running poorly at idle and is sluggish inbetween 2000 and 3000 RPM and all the problems I have heard of has been with the emmissions.

Are you SURE?

Have you tried looking HERE (http://www.sr20de.net/faq/index.html) first?

Or HERE (http://www.sr20de.net/car_info/problems/index.html)?

Why do you think I shouldn't go back to the JDM?
What for? Your problems are fixable.