Hello so I did a swap from a y5 to a y8 I’m using the y8 harness and ecu problem is car is continuing to prime I can get it started sometimes but sometimes not what am I missing. Also I have no rpm’s and my obd2 port not working

 

All HX chassis used the OBD-2A style engine harness that is most similar to the Y8 engine harness found in the '96-98 Civic EX... you stated that you are using a '00 Civic Y8 harness. This is NOT a "plug-n-play" solution. Get a '96-98 Y8 engine harness.

 

Could I get a jumper harness from obd2a to obd2b?

 

If you are trying to use the '00 P2P ECU, you will need an OBD-2A -> OBD-2B jumper harness. This doesn't solve the engine harness problem that I outlined above... you still need to solve that issue.

 

what’s different between the harnesses ? And could I use a 97 ek harness

 

Yes, you can use a '97 EK Y8 engine harness. On a manual EK engine harness, there are THREE plugs that connect to the ECU. In a '96-98 model, all three are found at the end of the engine harness. In a '99-00 model, two are found at the end of the engine harness and the last one is part of the dash harness. So, when you try and use a '99-00 engine harness in a '96-98 Civic chassis, you will be missing one plug at the ECU... and this is why your car doesn't work properly.

 

you mean I can use the 97 ek harness on my 97 hx with the 00 ex y8 motor? This is my harness right now btw

 

You will need to use the original HX engine harness on your '00 Y8 engine... and then you will also need an OBD-2A -> OBD-2B ECU adapter so that you can plug in your original '00 P2P ECU.

 

do I have to wire in anything

 

If you use the HX engine harness... you will have to re-wire the O2 sensor and distributor... if you use a '96-98 Civic EX (Y8) engine harness instead, you will not have to deal with the O2 wiring change. There is NO factory solution that will NOT require some wiring changes.

 

A '96-98 Y8 EX distributor will eliminate the distributor re-wire.