No, the valves on a 2000 Honda Civic may not be all the same. The number, size, and shape of valves depend on the engine configuration. For instance, the 2000 Honda Civic came with different engine types such as the D16Y7, D16Y8, and B16A2, among others. Each engine type has a different number of valves and valve sizes, so it's essential to consult the manufacturer's specifications to determine the proper valve configuration for your engine. Additionally, each cylinder head may have both intake and exhaust valves of different sizes and shapes that perform different functions. Therefore, it's crucial to ensure that the correct valve configuration is used during engine repair or maintenance to prevent any performance issues or damage.