Catalyst Efficiency Low (Bank 2)
P0430 indicates that the catalytic converter on Bank 2 (the side of the engine opposite cylinder #1) is operating below the required efficiency threshold. The oxygen sensors downstream of the converter detect that the converter is not reducing exhaust emissions effectively, often due to contamination, damage, or aging. This can lead to increased emissions and potential failure of emissions tests.
01. Most Common Causes
- Faulty catalytic converter (clogged, melted, or contaminated)
- Exhaust leak before the converter on Bank 2
- Faulty oxygen sensor (downstream) on Bank 2
- Engine misfire causing unburned fuel to damage the converter
- Oil or coolant contamination from engine issues
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Failed emissions test
- Possible slight decrease in fuel economy
- Rotten egg smell from exhaust (if converter is severely clogged)
03. Step-by-Step Diagnosis
Step 1: Scan for codes and verify P0430 is present; check for other codes like misfires or oxygen sensor issues.
Step 2: Inspect exhaust system for leaks on Bank 2 (between engine and catalytic converter).
Step 3: Monitor oxygen sensor data with a scan tool; compare upstream and downstream sensor readings to confirm converter inefficiency.
Step 4: Perform a backpressure test to check for a clogged converter.
Step 5: If all else is fine, replace the catalytic converter on Bank 2.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
Yes, but only short distances. Driving with a failed converter can lead to further engine damage, reduced fuel economy, and failed emissions tests. It's best to diagnose and repair promptly.
How much does it cost to fix?▼
Diagnosis typically costs $50-$150. Replacing a catalytic converter can range from $500 to $2,500 or more, depending on the vehicle and whether it's an OEM or aftermarket part.