Pesky P0420 trouble code

I still own my first Tacoma (2000 4wd 2.7L) with 261k. Every 2 years or so I get a check engine light and its always the P0420 code (catalyst below threshold bank). I've changed o2 sensors and it takes care of it for a while. I'm thinking its the converter going bad but the truck has the CA emissions package on it and there are 2 converters. Has anyone else had this problem and if so what did you do to fix it? Any help is greatly appreciated.

 

My MAF sensor was gunked up from the K&N, also welcome to the forums I'm from currituck

 

Had a exhaust leak fixed the leak no more code

 

You are definitely looking at a possibility of a bad catalytic converter. Getting 261K miles on one is not a bad lifetime for it. Do you have a scan tool that will give you live data? If so, look at the graph for your post cat sensor. If it is jumping up and down like the pre cat sensor, then you are looking at a catalytic converter that will need to be replaced, assuming that you have replaced both sensors and that there are no air leaks in your exhaust system.

 

I've replaced both O2 sensors a couple of times. I've even replaced the #2 cat since I have two on this truck. I'm gonna crawl underneath and. Check for leaks again but maybe it's just time to replace the cats.