In reply to alfadriver :
My understanding is that his car started as a USDM body, drivetrain, and computer. It now has an EDM engine, but still has a USDM body and computer. The USDM car had a knock sensor. He's mechanically mounting the USDM knock sensor in the same spot on the EDM engine, so that the USDM computer (which had a knock sensor) behaves itself.
