EmissionsSeverity Low: usually safe to drive

P0430Catalyst System Efficiency Below Threshold (Bank 2)

What it means

The downstream oxygen sensor shows that the catalytic converter on bank 2 no longer stores enough oxygen.

Symptoms

Check engine light
Failed emissions test

Common causes

Worn or damaged catalytic converter (bank 2)
Exhaust leak near the sensors
Faulty downstream oxygen sensor
Past misfires

What to check first

Compare upstream and downstream O2 signals on bank 2
Check for exhaust leaks
Fix misfires and fuelling faults first

Can I drive with P0430? Usually yes. P0430 rarely affects how the car drives, but it keeps the check engine light on and can fail an emissions test.

Generic OBD-II meaning. Manufacturer-specific meanings and checks can differ; always check the service information for the car.

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P0430: questions and answers

What does P0430 mean?

P0430: Catalyst System Efficiency Below Threshold (Bank 2). The downstream oxygen sensor shows that the catalytic converter on bank 2 no longer stores enough oxygen.

What are the symptoms of P0430?

Check engine light. Failed emissions test.

What causes P0430?

Worn or damaged catalytic converter (bank 2). Exhaust leak near the sensors. Faulty downstream oxygen sensor. Past misfires.

How do you diagnose P0430?

1. Compare upstream and downstream O2 signals on bank 2 2. Check for exhaust leaks 3. Fix misfires and fuelling faults first

Can I drive with P0430?

Usually yes. P0430 rarely affects how the car drives, but it keeps the check engine light on and can fail an emissions test.