Can a 2001 astro van lose power up hill by bad catalytic converter?

Yes, a bad catalytic converter in a 2001 Astro van can cause a loss of power, especially uphill. A clogged or failing catalytic converter restricts exhaust flow. This backpressure can significantly reduce engine performance, making it struggle to maintain speed, particularly under load (like climbing a hill). While other issues can cause similar symptoms, a failing catalytic converter is a strong possibility.