Q&A

got the 0420 code, replaced the O2 sensors as well as the Catalytic converter. The CEL turns on after driving for about an hour (going through the drive cycle as well). The car has 195k miles and most of the parts are original except the motor itself that I purchased from a recycler not too long ago with an estimated 50k miles. Not sure which direction to take to troubleshoot. Registration is expired and need to find a solution. Any help would be appreciated, thank you.