Hello everyone, I am working on a F20B+T2T4 swap into a 1998 2.3CL with a manual trans. Since I have a full engine harness and PCB ECU for the F20B I will be simply re-routing the harness to the correct side and extending anything that is too short and running the JDM ECU.

My question is, what can I unplug from the CL ECU without throwing any codes? I want to keep everything OBD2 compliant and keep cruise control so I will be running both ECUs at the same time in parallel. Using the CL diagram, the only things I can see that I can unplug are the injectors, is there anything else that the ECU doesn't need to see to function? Basically I just want to use the JDM PCB ECU as a piggyback without the CL ECU interfering with fueling, spark, or vtec. For that matter, do I need to use a resistor for the injectors or can I just leave them unplugged?

I know I will need to keep the sensors plugged in, but are there any other ECU outputs that the ECU doesn't have feed back for, as an example, do I need to have the fuel pump relay connected to the USDM ECU, or will it be fine if I connect it to just the JDM ECU?

Thank you in advance