P0430
Catalyst system efficiency below threshold (Bank 2)
The ECU has determined that catalytic-converter efficiency on Bank 2 is below the expected threshold.
What this code means
The ECU has determined that catalytic-converter efficiency on Bank 2 is below the expected threshold.
Possible causes
- Aged or damaged catalytic converter
- Exhaust leak
- Oxygen-sensor fault
- Misfire or mixture fault damaging catalyst performance
Common symptoms
- Check engine light
- Often no obvious driveability symptoms
- Possible emissions-test failure
Checks to make
- Check for misfire and fuel-trim codes first
- Inspect exhaust for leaks
- Compare upstream and downstream O2 sensor activity
- Confirm catalyst condition before replacement
Safety
- Do not replace parts from the code alone. Confirm the fault with live data, wiring checks and manufacturer procedures. Keep clear of hot or moving engine components.
Model notes
The code definition is generic; exact diagnostic thresholds, component locations and repair procedures vary by vehicle.