What effect can a faulty exhaust system have?

A faulty exhaust system significantly increases the vehicle's noise and pollution levels. The exhaust system's primary role is to direct harmful gases produced during combustion away from the engine and reduce emissions using various components, such as catalytic converters. When the system is malfunctioning, it may allow these gases, which include carbon monoxide, nitrogen oxides, and hydrocarbons, to escape into the environment, leading to greater pollution.

Moreover, a compromised exhaust system can result in increased noise levels as it may not effectively muffle the sound produced by the engine, making the vehicle louder than it normally should be. This not only contributes to noise pollution but can also indicate underlying issues with the engine's operation, which should be addressed for both environmental and safety reasons.

The other options do not accurately reflect the implications of a faulty exhaust system; it does not reduce fuel consumption or enhance engine performance, nor is it true that it has no effect on emissions. Instead, a malfunctioning system typically exacerbates pollution issues, highlighting the importance of regular maintenance for vehicle exhaust systems.