In the 4.0L V6 models, the knock sensor is located in the valley between the cylinder heads below the intake manifold, which has to be unbolted to get access to the sensor. First of all, the cable must be disconnected at the negative terminal of the battery. Following the above, rip off the intake manifold. Follow the knock sensor wire back to the sensor's electrical connector and remove it. Turn the knock sensor mounting bolt counter clockwise and pull out the knock sensor. Removal is basically the same to installation, tightening the knock sensor retaining bolt to the required torque. For 3.7L V6, 4.6L and 5.0L V8 engines sensors are located in the valley between the cylinder heads, under the intake manifold and that requires removing the intake manifold to access either of them. These engines are fitted with two knock sensors which are in a single harness and connector and hence must be replaced as a pair. First of all, unscrew the cable from the negative battery connection then take of the intake manifold. Follow the two leads coming from the knock sensors to the electrical connector that joins the two of them and cut that. Loosen the knock sensor retaining bolts, and while on 4.6L V8 engines, the two knock sensors have different electrical leads but are connected to a single electrical connector therefore have to be removed or replaced as a pair. Reinstallation proceeds in the reverse manner to the removal process so as to ensure that knock sensor retaining bolts are tightened to the recommended torque.