WRENCHIFY
Quick decodeBack to home
All codes/P0430

P0430

Catalyst System Efficiency Below Threshold (Bank 2)

Moderate severity

Similar to P0420, but this code indicates the catalytic converter on the engine's second bank (if your engine has two) isn't cleaning exhaust gases efficiently.

The powertrain control module (PCM) has detected that the catalytic converter system for Bank 2 is not operating at the required efficiency.

Common causes

  • Failing Catalytic Converter

    The most frequent cause, especially in high-mileage vehicles, indicating degradation of the catalyst material in Bank 2's converter.

    high

    Typical part cost: $500-2500+

  • Oxygen Sensor (O2 Sensor) Malfunction

    A faulty O2 sensor (upstream or downstream) on Bank 2 can provide incorrect data, leading the PCM to misinterpret converter efficiency.

    medium

    Typical part cost: $100-300

  • See all causes + fix costs

    Create a free Wrenchify account to unlock the rest for P0430.

    Unlock causes

    Free forever · No credit card

First things to check

  1. 1Scan for other related codes, especially misfires or O2 sensor codes specific to Bank 2.
  2. 2Visually inspect the exhaust system on Bank 2 for any leaks, damage, or loose connections.

Get the full step-by-step diagnosis

Create a free Wrenchify account to unlock the rest for P0430.

Unlock diagnosis

Free forever · No credit card

Tools you may need

Already have a compatible scanner? Use it. If not, a Bluetooth OBD2 adapter can help you confirm engine codes and check supported live sensor data before replacing parts.

Illustration of a Bluetooth OBD2 adapter, not a product photo

Basic checks

Veepeak OBDCheck BLE

A Bluetooth LE adapter for reading standard engine codes and supported live data.

View on Amazon
Illustration of a Bluetooth OBD2 adapter, not a product photo

Regular diagnostics

vgate iCar Pro BLE 4.0

A Bluetooth LE adapter with an automatic sleep feature for routine code and sensor checks.

View on Amazon
Illustration of a Bluetooth OBD2 adapter, not a product photo

Another option

OBDLink CX

A Bluetooth LE adapter to consider when comparing supported vehicles and diagnostic apps.

View on Amazon

Illustrations shown, not product photos. Check vehicle, phone and app compatibility before buying. These adapters do not guarantee access to ABS, airbags or manufacturer-specific systems. Clearing a code does not repair the fault and can reset emissions readiness monitors.

As an Amazon Associate, Wrenchify earns from qualifying purchases. This supports the app at no extra cost to you.

Related codes

See related trouble codes

Create a free Wrenchify account to unlock the rest for P0430.

Unlock related codes

Free forever · No credit card

Frequently asked questions

What's the difference between P0420 and P0430?

P0420 refers to the catalytic converter on Bank 1 of the engine, while P0430 refers to the catalytic converter on Bank 2. Bank 1 is typically the side of the engine with cylinder #1.

Will a P0430 code prevent my car from passing inspection?

Yes, in most regions that require emissions testing, a P0430 code will cause your vehicle to fail inspection because it indicates the emissions control system is not functioning correctly.

Get the full P0430 diagnosis for your vehicle

Year, make, model + step-by-step repair help — free plan included.

Diagnose P0430