Trouble Codes

P0430 – Catalyst system efficiency below threshold Bank 2

błąd p0430 code

OBD2 error P0430 possible causes

The reasons that may lead to the establishment of P0430 may be as follows:

  • Damage to Bank 2 catalyst
  • Intake air leaks
  • Fuel injectors may be faulty
  • Fuel injector leaks
  • Spark plugs may be damaged
  • Incorrect ignition time
  • Failure of the engine control module (ECM)
  • Dirty air filter

Technical notes

According to the code description, code P0430 means that the vehicle’s control unit has detected that the three-way catalytic converter is not working properly (not as efficient as expected by the factory). Replacing oxygen (O2) sensors can sometimes fix the code, but in most cases the catalyst must be replaced to fix the problem. If code P0430 is combined with other codes, try to repair the remaining faults first.

When will the code be detected?

  • Bank 1 three-way catalyst does not work properly.
  • The Bank 1 three-way catalyst does not have sufficient oxygen storage capacity.

Possible symptoms

  • Engine failure light comes on
  • Flashing engine light during acceleration

P0430 Code description

The engine control unit (ECM) monitors the switching frequency ratio for heated oxygen sensors 1 (O2 front sensor) and heated oxygen sensors 2 (O2 rear sensor). A three-way catalytic converter with a high oxygen storage capacity will indicate a low switching frequency for heated oxygen sensor 2. When the oxygen storage capacity drops, the switching frequency of the second lambda sensor will increase. When the ratio of the frequency of the heated oxygen sensors 1 and 2 approaches the specified limit, a malfunction of the three-way catalytic converter is diagnosed.