OhioSI

Hi guys this is my first post on the forums so be easy on me. I picked up a close to stock 2000 civic Si about a year ago. I've been chasing a IACV problem for the whole time and Ive replaced nearly everything mechanically that could cause the problem and even tried swapping for a stock ECU for a friends stock ECU. At this point I'm pretty sure the problem is somewhere in the wiring harness, I haven't been able to find a short between the IACV and the ECU so I plan on putting a new engine harness in. What engine harness is directly interchangeable with an EM1? I've heard that an EX harness will work but I want to make sure before I go searching through every junkyard in central Ohio.

Thanks

HondaPartsHero

EX harness will work, the distributor plug is different. I also believe the CKF plug differs as well.

OhioSI

So I would have to modify the harness for it to work? Also does it have to be a 99-00 harness or can it be any EK ex harness?

1999 Civic Si

The only direct plug and play, with no modifications, OEM engine harness for your car is a 99-00 Civic SI harness (USDM, not sure on other models outside the USA), it will have to be a 99-00 Civic Si or EX (manual transmission). Like stated above the distributor plug is different and you have to extend the vtec wiring a few inches.

Also be prepared to fork over a few bucks for a clean used SI engine harness (no longer available new), it is fairly straight forward to remove and swap out the harness, I did it with no prior knowledge of how to remove or install it in about an hour total, getting to the CKF plug is somewhat of a pain.

tony_2018

It has to be 99-00 OBD2B, right there not some 96-98 OBD2A bullshit.

OhioSI

Ok thanks guys I'll report back if I run into any more trouble.