Hey bro, I am in CA as well. I have a few tricks to get past the p0420 cat converter problem. Without replacing the stupid thing! I'm in San Bernardino and would like to offer any help I can. I worked nights for over 2 decades and you sound a lot like me in fixing old cars. LMK if you are interested in the info. The fixes are between $5 and $50. The cheap way usually works best in my experience.
