I have an i have a 97 jdm h22a in my 97 ek hatch. know i have the the obd2a harness in my car. my friend lent me an ecu he had laying around with no id on it. i look around on the net and i found it to be a usdm 99-00 si ecu. i know the computer uses the obd2b style. Now my ? is can i just buy an obd2a-obd2b jumper and just plug that ecu and run it ?

 

you could do that but it probaly wont run very well with the si map on it seeing as the motor is a lot smaller

 

cause im running a obd2a-obd1 harness w/ a chip p13. oh ok, then y is it some people run p28's, p30's, or p72's on h22a or mix match ecu to different motors ? sorry just another ?

 

im pretty sure for obd-1, that the h22 runs decent off the p72 (gsr i think). i just wouldnt like using an ECU like that because it is not made to run the amount of fuel the h22 needs.
im not sure what you need though because its obd2a to obd2b

 

so the p72 obd1 gives more fuel then the P2T obd2b ?

 

im not sure about the differences between obd1 and obd2 because my car is obd1. i would think if your engine and car are both obd2, it would be easier to stick with an obd2. if you are really worried about an ECU, check to see if you can find an aftermarket chipped ecu to run a h22 basemap. i got mine from phearable.net, very easy guy to work with.