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P0422 - OBD-II Trouble Code

Our automotive experts have put together the following information about the P0422 diagnostic trouble code. We've provided the common symptoms that occur when this code is set along with the frequent repairs that address the issues related to the P0422 code.

OBD II Fault Code

  • OBD II P0422

Fault Code Definition
Code P0422 indicates that the Bank 1 Main Catalytic Converter's emissions efficiency has fallen below the minimum allowable limit. This threshold is tracked by a Catalyst Monitoring Oxygen Sensor located on or near the outlet of the Catalytic Converter.

Symptoms

  • Check Engine Light will illuminate
  • In many cases, no abnormal symptoms may be noticed

Common Problems That Trigger the P0422 Code

  • Defective Catalytic Converter
  • Engine misfires have damaged the Catalytic Converter
  • Internal engine damage resulting in high oil consumption and/or a leaking Head Gasket has damaged the Catalytic Converter

Common Misdiagnoses

  • Oxygen Sensor(s) are replaced when the real problem is a damaged Catalyst
  • Catalyst is replaced when the real problem is internal engine damage, which is producing elevated emissions levels
  • Catalyst is replaced when a misfiring engine is the real problem