tell me if i am right...I have a 98 ex harness going to repin it so it can plug into my 99 si ecu for my swap, am i doing it right? did i miss anything or i have to add extra wires, or is there any wire from the ex harness dont need for the si ecu? plz guys help me, thankz

 

The 96-98 harness isn't a direct bolt on.

In order for you to get it to work, you're basically gonna hve to repin each plug. It's a nightmare and probably not worth your time.

If you really want to run this set up, get a ecu harness converter.

 

how much does that harness converter cost? so basically I dont need to add any extra wires to the si plugs? all the wires from the ex harness will match up the si ecu?

 

what's your setup? what are you planning on doing?

 

you'll need an obd2a->obd2b converter harness...I dont know where to get em (but I heard hondata will make it for you)

 

Kenji or Blown90Hatch can make them for you.

I bought parts from both of them and made one myself.

 

well, I have a 97 hatchback w/ 99 si motor using 97 gsr ecu now, but the car is running really slow, and the vtec is so weak, so I was planning to use the Si ecu to see how it is..

 

Okay, that helps. The best thing to do would be run a harness.

But the only thing is, you'll have a code 91. The OBD2b ecus look for a sensor that you don't have. So, be prepared for that. Or, you can try and find a friend with a chipped ecu and a harness, that would probably be better.

 

best thing is going to be getting a convertor harness. i got mine from a guy in fl email is kenji211@tampabay.rr.com he did mine for 200 shipped and it is the best looking convertor i have seen, he kept the wire colors even stock. a 99 ecu is going to throw a 02sensor code unless you run a factory cat and 2nd 02 sensor.
i have a p30 ecu for sale e-mail me if your interested. you would have no o2 sensor problem but would still need a convertor harness.

 

what is code 91? what sensor that my hacthback dont have?
I m running a factory cat and also has the 2nd 02 sensor.