I put a 99 ex motor in a 96 ex. I used the 96 ex harness and ecu. The distributor plugs didn't match up so I cut the plug off my old 99 harness and soldered it to my 96 harness to plug into the 99 distributor. All the colors pretty much matched up.

There was a blue wire left over on my 96 harness. This wire usually goes under the distributor cap to read rpm for the tach. So I opened the 99 distributor cap and saw the empty terminal for this wire to connect to (99's don't utilize this terminal, they run the wire to the ecu. but I am using the 96 ecu).

So I start the car. The tach dosn't work for crap, it sits at 0. Sometimes if I rev the car to 3k, the tach will jump to 7k or so. The car idles funny and hesitates when I hit the gas pedal. I am also getting a code 4 CKP.

I did a bunch of research and alot of the websites said CEL code 4 CKP is related to the distributor/wiring. Should I just put the 96 dizzy in the 99 motor, Solder the 96 dizzy plug back onto the 96 harness? Is there a chance this would get rid of my code, solve the hesitation, and give me a tach?

 

If you have a 96 ex dizzy then put it on and use your 96ex harness

 

I'm confused, this motor should be exactly the same throughout the generation. You sure both motors had the same engine code?

 

doesn't the 99-00 use the OBD2b ecu and the 96-98 use the OBD2a.

 

Yes.

What you need to do is, Use your 96 Dizzy, Alternator, Harness, and ECU. Your dash harness will not work correctly with a 99 Harness, the pinning in the green connector is different. Im pretty sure OBD2A and OBD2B injectors are the same but don't hold me to that, ive never owned an OBD2b car.

Remember on Civics 92-95 OBD1, 96-98 OBD2a, 99-00 OBD2b