2002 Lexus IS300 How can you tell if the catalytic converter is bad or just the sensor bank 2?

To determine if the catalytic converter is bad or if it's just the bank 2 sensor, you can start by checking for warning lights on the dashboard, such as the check engine light. Use an OBD-II scanner to read any error codes; codes related to the catalytic converter (like P0420) indicate potential issues with it, while codes specific to the sensor (like P0138 for bank 2) suggest a sensor problem. Additionally, you can inspect the exhaust system for unusual noises or smells, and perform a visual check for physical damage or clogs in the catalytic converter. If the converter is excessively hot or glowing after driving, it may be failing.