The catalytic converter is going to be covered under the Federal Emissions Selected Components warranty which for the 2003 Pontiac's is 8 years/ 80,000 miles (or 7 years/ 70,000 miles depending on what state you live in... there's different emissions laws in some places like California, New York, Rhode Island, etc). You should be totally covered if it's the catalytic converter, just take it in to the local pontiac dealership. Even if you are a little over on miles, most dealers will go ahead and do the work for you. If the dealer gives you a hard time, just call the Pontiac Customer Assistance Center (800-762-2737) and they will help you out!
