I have never had the dreaded P0420 code for possibly bad catalytic converter. Some people online have commented that non-OEM converters may not last. Living in the original CARB state of california I was wondering if anyone had any experience with the longevity and effectiveness of these more stringent catalytic converters? One local guy that has to use OEM converters for Toyota Prius's said they have can recommend Walker and Magnaflow Calif. approved applications. I would appreciate anyone that has had working opinions with aftermarket converters. Thanks in advance.