What can cause P0421?

What can cause P0421?

The most likely failure that causes this code is the Catalytic Converter, but oftentimes the Catalytic Converter can fail due to the engine running poorly. Always make sure the engine is running properly before replacing the Catalytic Converter.

How do I fix error P0421?

What repairs can fix the P0421 code?

  1. Replacing the catalytic converter.
  2. Replacing the oxygen sensor.
  3. Repairing or replacing wiring that is associated with the oxygen sensor.
  4. Replacing the powertrain control module.

What does warm up catalyst efficiency below threshold mean?

Diagnostic trouble code (DTC) P0431 stands for “Warm Up Catalytic Converter, Bank 2—Efficiency Below Threshold.” It means that your car’s primary computer or powertrain control module has detected that the catalytic converter is not efficient enough based on factory specification.

Does P0421 mean oxygen sensors?

This data is used by the PCM to compute fuel delivery strategy and ignition timing, as well as other things. If the upstream and downstream O2 sensors reflect a similar exhaust oxygen concentration, a code P0421 will be stored and a malfunction indicator lamp may be illuminated.

How do you warm-up a catalytic converter?

A very elegant method to speed the warm-up is the use of the engine itself as a “preheater” for the catalytic converters. High exhaust gas enthalpy to raise exhaust system mass up to its operating temperature is obtained by the use of extreme spark retard, stochiometric mixtures, and fully opened throttle.

How long does it take for a catalytic converter to warm up?

David DaCosta, president of the company, says: “It takes the catalytic converters on today’s cars between one and two minutes to reach ‘light-off temperature’, which is about 350 °C. Before they heat up, the exhaust and unburned fuel go right through.”