ok how does the knock sensor wire come off, of course the one I have is not the correct one so have to get another one, do you just push it sideways and it comes off or what. the leak was the small piece that goes to the fuel rail, what I thought was the return line was not a fuel line after all. Roy since have to wait on the sensor I will order the o-ring also because there was some coolant on top under the manifold.