Knock sensor location and installation instructions needed

There are two knock sensors on that engine, do you have a code telling you which sensor is the issue or is it something else that points to a bad sensor? The front B1 sensor is behind the starter motor on the front of the engine just above the oil pan screwed into the block. The rear B2 sensor is in the middle of the block just above the oil pan, it is behind the heat shield between the exhaust manifold and the block. Both sensors screw into the water jacket of the engine so replacing them requires the coolant be drained or using something like a vacuum lift or other trick to keep the coolant from leaking out when they are removed.