Discover Toyota 4 Runner Exhaust System Kit & Toyota 4 Runner Exhaust System Parts Replace Toyota 4 Runner Exhaust System. Maintaining the emissions system of your Toyota 4Runner is crucial for both environmental stewardship and optimal vehicle performance. Regular checks of the oxygen sensors, catalytic converter, and EGR valve can help catch issues early, preventing costly repairs and extending the lifespan of these components. When choosing replacements, opt for OEM-quality parts that ensure compatibility and longevity. The 4Runner's emissions system is designed to reduce pollutants, so using high-grade materials is essential for durability. For seamless installation, always follow the manufacturer's guidelines, and consider professional assistance to guarantee that your 4Runner runs cleanly and efficiently, keeping both the environment and your engine in prime condition.