How do you change a knock sensor on a 2003 Toyota Sienna?

To change the knock sensor on a 2003 Toyota Sienna, first disconnect the negative battery terminal to ensure safety. Locate the knock sensor beneath the intake manifold, which may require removing the manifold for easier access. Disconnect the wiring harness from the sensor, then unscrew and remove the old sensor. Install the new sensor, reconnect the wiring, reassemble the intake manifold, and finally reconnect the battery.