I get a P420 code along with the P1133 code for 99 Lexus ES300,
I get a P420 code along with the P1133 code for 99 Lexus ES300, I've changed O2 Sensor under motor towards firewall, and the 02 Sensor on front of engine by radiator. I used aftermarket sensors, and is that my problem. Not sure what the P420 means. Thanks for any help