Recently, I had performed a JDM D15b head swap onto a D16y8 block. I put my stock injectors back in and it is giving me a CEL 45. I also have noticed the car bogs when idling on occasion and the car's rpm will drop very low and often cut off when I let go of the gas. My IACV seems to be operating fine. I get no code 14 CELs, just the code 45. My fuel setup before I put the head in was DSM 450ccs, a 255 lph walbro fuel pump, and an AFC for the turbo setup, but was removed along with the turbo setup. To try and remedy and questionable areas, I changed the wire harness and injectors back to stock, but the fuel pump is still the same. Any ideas as to why this is occuring?