Find Toyota Sienna Manifold Catalytic System Location & Toyota Sienna Catalytic Converter With Integrated Exhaust Manifold. To ensure your Toyota Sienna runs smoothly, proper maintenance of the Catalytic Converter with Manifold is crucial. Regularly inspect for signs of wear such as rattling noises, decreased fuel efficiency, or a sulfur-like smell, which indicate a replacement might be necessary. Extend its lifespan by maintaining a steady driving style and using high-quality fuel to prevent clogging. When choosing a replacement, consider direct-fit models for ease of installation or universal converters for a cost-effective solution, each designed to meet emission standards and enhance engine performance. Opt for durable materials like stainless steel to ensure longevity. With the right care and choice, your Sienna's emissions system will remain efficient and compliant.