I am swapping an ITR longblock into my 4-door GSR that I blew the motor in. Planning to purchase an ITR ecu that will plug in to my stock gsr wiring harness for the swap - (1996 - 1999 obd2a).

I understand that the JDM ecu only looks at the first O2 sensor.

If I get a JDM itr ecu, does it completely get rid of the need for the second o2 sensor? Can the car function perfectly well on just the first O2 sensor? Still perform the same? Get the same gas mileage, etc...?

What is the point of the second O2 sensor other than to tell you that your cat is bad? Is this the only point?

Are there any downsides to running the JDM ecu vs. the USDM ecu? From everything that I have read - it looks like it should plug in to the stock 1996 gsr harness and work with no mods - but please correct me if I am wrong.

Thanks for your help!

Pinout thread that I found helpful - https://honda-tech.com/zerothread?id=794381


Modified by 96_GsR_BlownEngine at 7:48 AM 7/24/2004

 

Any help would be appreciated.

 

man all i know is when i had my gsr and put Ctr cams and Itr jdm pistons in i was running obd2 gsr ecu,after switching to the jdm itr ecu it was a whole diffrent world...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 1Quikgsr &raquo;</TD></TR><TR><TD CLASS="quote">man all i know is when i had my gsr and put Ctr cams and Itr jdm pistons in i was running obd2 gsr ecu,after switching to the jdm itr ecu it was a whole diffrent world... </TD></TR></TABLE>
Did it plug right in with no additional mods / issues? Were you using the obd2a ecu - 1996-1999?

I think that not needing the 2nd O2 sensor would be a plus anyway - would make it easier to use a test pipe w/o CEL.

 

The JDM itr ecu doesn't look for a secondary o2 sensor and if it does it doesn't throw a code if there isn't one plugged it. The USDM itr ecu does and will throw a code if one isn't plugged in. The only purpose the secondary o2 sensor servers is to determine if your cat. is in good working condition.

If your car is obdIIa than you wont need any converting harness's to run the jdm itr ecu, it should plug right in. The only thing that might be considered a downside to running a jdm itr ecu compared to the usdm one is that theres a speed limiter which is 120mph but reads 130mph on the stock speedometer.

 

Here's a dyno between a JDM R ecu (red) and a USDM R ecu (blue). Not a whole lot of difference in terms of power. The engine is a JDM B18cR with CAI and exhaust.



Like 2kgs-R said with an obd2a, you should not have any issues with the secondary o2 sensor with the JDM ecu since it's not looking for it.

 

Thanks guys! I think that I am going to get a odb2a JDM ITR ecu for sure