2000 Subaru Impreza Outback 2.2L P0420 Fault Code: Cat Converter Issue Diagnosis
Oxygen sensor resistance tests are generally considered unreliable, especially when diagnosing a P0420 code. However, if the sensors pass resistance checks and the fault is specifically identified as P0420 rather than an oxygen sensor issue, it's unlikely that replacing the O2 sensors would resolve the problem. While some Chrysler vehicles disable cruise control when engine timing is off, there is no known evidence linking this behavior to Subaru models. Given that the vehicle runs normally with the check engine light on and no other mixture, timing, ignition, or fuel-related fault codes present, it's reasonable to conclude that the catalytic converter may be the root cause of the P0420 issue.
Thanks for the reply. If the O2 sensors are functioning properly and there are no other issues related to fuel mixture, timing, or ignition (as confirmed by the vehicle running normally with the check engine light on and no additional fault codes), then the catalytic converter is likely the source of the P0420 code.