How can carbon deposits affect engine performance?

Carbon deposits can significantly impact engine performance by blocking air intake and exhaust flow. Over time, carbon can accumulate in various parts of the engine, including the intake valves, combustion chamber, and exhaust ports. This buildup restricts the flow of air and exhaust gases, which can lead to decreased engine efficiency and reduced power output.

When air intake is impeded, it results in a less optimal air-fuel mixture, potentially leading to incomplete combustion. Similarly, blocked exhaust flow can increase back pressure in the exhaust system, causing the engine to work harder to expel gases. This situation not only diminishes overall performance but can also increase emissions and lead to potential engine damage if not addressed.

In contrast, the other options suggest effects that are contrary to the nature of carbon deposits. They do not enhance air intake or improve fuel economy; rather, they typically detract from an engine's operational efficiency and can create additional noise due to the strain on engine components. Recognizing the impact of carbon deposits is crucial for maintaining optimal engine performance.