CA Emission codeP0420

Has anybody had this code for a 2000 4runner with 3.4L, replaced both sensors and cats. Also looked for leaks and found none. Unable to get rid of this code any suggestions or help will greatly appreaciated.

Thanks

Could be a fault in the A/F ratio or HO2 sensor wiring or connections. I would bet on the HO2 sensor wiring/connection.