The knock sensor on a 2003 Chevy 6.0L engine (likely an LQ4 or LQ9) is located on the
passenger side of the engine block,
near the rear of the engine. It's usually
mounted in the valley between the cylinder heads, often close to where the oil filter is located. However, its exact position can vary slightly depending on the specific engine configuration and potentially even the year of manufacture within the 2003 model year.
Because of its location, it can be somewhat difficult to access. You'll likely need to consult a repair manual or a detailed diagram specific to your year and engine code to pinpoint its precise location. A service manual with diagrams would be your best bet for confirming.
