Ok guys hopefully I can get some useful info here and learn a few things along the way. Now first off I know there is a wire jumper harness available by boomslang @ boomslang.us/aem-ems-4.php and go from there, but can we go cheaper and take the 15$ OBD2A-OBD1 jumper harness and hardwire in the ems 4 wire harness successfully? I haven't found anything of this sort done by any one yet so if it's out there any help would be nice. I have a 97 honda civic running a boosted b18b obd2A harness with a jumper to the obd1 ecu. I recently purchased a aem ems 4 and would like to keep the obd1 ecu hooked up to run the dash. Been looking at the different wire diagrams and I dnt see why I couldn't save $400 and do it my self. Just need some walk throughs and later posy a full diy thread.

 

the $15 jumper harness will cause nothing but problems. it costs $15 for a reason.
and with an ems4 in the mix, do you really want to risk destroying that too?
get the proper plug and play harness if you want to prevent very expensive future issues.

for the record, I was a boomslang dealer for about 8 years, and never saw a single failure, ever.
but those cheap $35 and less jumper/conversion harnesses, well, I've never seen a single one actually last more than a couple years. and when they fail, they often cause engine damage and/or ecu damage. so to modify a crappy harness yourself, seems to me would only increase the chances of failure.

 

Well said.