F23A1 to H23A VTEC swap throwing Cel P0400 I went to check out the progress of the swap. The engine is in and looks good. My mechanic started it up and it's running fine but when we took it for a ride, it threw a cel code and started flashing. We kept the original OBD II wire harness and ran my F23A1 OEM ECU. Will the P5P work with the H23A or will I need a JDM ECU. My mechanic tells me that a JDM ECU won't work due to the EGR sensor being 2 wire for JDM and 3 wire for USDM. What is the best way to wire a JDM ECU with a USDM harness?