To locate it, you'll need to:
1. Consult a repair manual: A repair manual specific to your Silverado's engine will have diagrams showing the exact location of the EGR valve. This is the most reliable method. You can often find these online (for purchase) or at an auto parts store.
2. Look at the intake manifold: The EGR valve is usually mounted on the intake manifold, somewhere near the back. It's a small, rectangular or cylindrical component with vacuum lines connected to it. It often has an electrical connector as well.
3. Search online for your specific engine: Search online using a combination of terms like "2003 Chevrolet Silverado [your engine size] EGR valve location". Many forums and websites have pictures and descriptions that can help you pinpoint it. Look for images showing the engine bay from different angles.
4. Trace vacuum lines: If you're comfortable working under the hood, you can try tracing the vacuum lines. Follow the lines that lead to the intake manifold; often, they'll connect to the EGR valve.
Important Safety Precautions:
* Always disconnect the negative battery terminal before working on your vehicle's engine.
* The engine and surrounding components will be hot if recently run. Allow it to cool completely before working on it.
* Be careful when working near hot exhaust components.
Without knowing your specific engine size, I can't give you a more precise location. Using the repair manual is strongly recommended to avoid damaging other parts of your engine.
