1. OBD-II Scanner: Use an OBD-II scanner to read the diagnostic trouble codes (DTCs) stored in the vehicle's computer. Codes such as P0420 or P0430 indicate catalytic converter issues. 2. Visual Inspection: Check the catalytic converter for physical damage, discoloration, or signs of overheating. 3. Exhaust Backpressure Test: Measure the exhaust backpressure to determine if the catalytic converter is clogged. 4. Temperature Test: Use an infrared thermometer to measure the temperature difference between the inlet and outlet of the catalytic converter. A significant difference may indicate a problem.
