P0430
Moderate Severity

P0430 — Catalyst System Efficiency Below Threshold (Bank 2)

System: Emissions

What P0430 means

Diagnostic Trouble Code (DTC) P0430 stands for Catalyst System Efficiency Below Threshold (Bank 2). This is a generic OBD2 diagnostic trouble code indicating that the engine computer (ECU) has registered an operational anomaly in the powertrain (p) systems.

When this error registers, the ECU records a freeze frame of sensor data and lights up the Check Engine Light on your dashboard to notify the operator of a system fault.

Symptoms of OBD2 Code P0430

When code P0430 is active, your car might exhibit the following common symptoms:

  • Check Engine Light on
  • Loss of engine performance at high speeds
  • Slightly increased fuel consumption
  • Rotten egg exhaust odor

Common Causes of Code P0430

Faults that trigger this code typically include:

  • Cause 1: Failing Bank 2 catalytic converter
  • Cause 2: Exhaust leak on the Bank 2 side of the engine
  • Cause 3: Faulty Bank 2 downstream oxygen sensor
  • Cause 4: Engine oil or fuel dumping into Bank 2 exhaust

Can you drive with a P0430 code?

Yes, but minimize long-term driving to prevent downstream exhaust blockages or catalyst core degradation, which can lead to backpressure issues.

Expected Repair Cost Band

$800 - $2,500 for a new Bank 2 catalytic converter. Upstream leak repairs cost $150 - $400.

Related Diagnostic Trouble Codes

If you have scanned multiple codes, see these related guides for troubleshooting context:

Frequently Asked Questions

What is Bank 2 in P0430?

Bank 2 refers to the side of the engine that does not contain Cylinder #1 (often found in V6, V8, or boxer engine layouts).

Can I drive with a P0430 code?

Yes, temporarily. But avoid ignoring it, as a fully failing converter can clog the exhaust and stall the engine.