u/Conscious-Owl-5546

Hi, my lexus 2006 rx400h has p0420 code for almost 2 years. Its at 186k miles. Now it needs to pass smog check here in california bayarea (its needed every 2 years), so looking for options to install new carb compliant catalytic converter. P0420 means i need it for bank 1. Already replaced o2 sensor but it didn't help. Has anyone got this work done? How much did it cost? I see Lexus oem exhaust manifold plus catalytic converter for $600-700 online new. Does this sound about right? And how much will be labor?

Other than this, the car drives fine! Recently I had to open the exhaust to free up the clogged exhaust. It was completely clogged with black coal like material which were probably the internals of burned catalytic converter.