Okay this is my delima. I had a B16a JDM engine and Trans in My 1990 CRX HF. I blew that motor and got a B18a from a automatic Integra. I swapped the auto trans for my manual trans from my B16a. I swapped the motor and dropped in the Newly acquired B18a with my B16a Trans mounted to it. I have some confusion of which ECU to use while I wait for my ECU I bought off of ebay which is made for a manual trans B18a (PR4). Now there are a couple extra harnesses from the B18a that doesn't have anyplace to connect to. I also have the transmission sensor hanging off in la la land. My question after all of this explanation is, Which ECU should I use first? And I am in the process of going thru the wiring diagrams for both engines and cars to figure out where goes where. I was hoping someone had done this before and can let me know what wires need to go where and if there are any "clean" ways of running wires or keeping the engine compartment clean of all those wires? Thanks for checking this out and please let me know if there are anything else I should know or look for before chugging down the road. Thanks again!! Aloha