2001 MPV P0421 Fault: Does It Require a Catalyst Converter or Oxygen Sensors?
I'm experiencing a P0421 diagnostic code on my 2001 MPV. Does this indicate the need for a catalytic converter replacement or faulty oxygen sensors? Any guidance on troubleshooting steps would be greatly appreciated.
You can monitor the oxygen sensor readings to assess their performance. If the O2 sensors are functioning properly, the issue is most likely related to the catalytic converter.