Catalyst System Efficiency Below Threshold (Bank 2)

What is P0430?

P0430 indicates the catalytic converter on Bank 2 (the side of the engine opposite cylinder #1) is not cleaning exhaust gases as efficiently as expected. This is a medium-severity powertrain code that typically triggers when the downstream oxygen sensor detects too little difference from the upstream sensor, suggesting the catalyst isn't working properly. Based on real data, this code is commonly reported on Toyota 4Runners, Ford F-150s, and Honda Accords, with repair costs averaging $3542.

Common Causes

• ●Failed or degraded catalytic converter (most common cause based on repair patterns)
• ●Faulty oxygen sensor(s) providing incorrect readings to the ECU
• ●Exhaust leaks before or after the catalytic converter allowing unmetered air to enter

Symptoms You May Notice

• ●Illuminated check engine light (the primary symptom owners notice)
• ●Potential slight decrease in fuel economy reported by some drivers
• ●No noticeable drivability issues in many cases, as owners often report normal driving

How to Fix It

• ●Replace the Bank 2 catalytic converter ($1000-$4800, high difficulty due to exhaust work and potential rust)
• ●Replace one or both oxygen sensors ($150-$400, medium difficulty for DIY if accessible)
• ●Diagnose and repair exhaust leaks ($200-$800, medium difficulty depending on leak location)