P0433 Catalytic converter: efficiency too low (heated catalyst, bank 2)
P0433 means: Catalytic converter: efficiency too low (heated catalyst, bank 2). The catalytic converter cleans the exhaust gas. OK to drive, but have it checked soon. The most common repair costs about €450–900 in Estonia, depending on make and model. The most common cause: old or damaged catalytic converter.
What it means
The catalytic converter cleans the exhaust gas. The computer compares the oxygen sensors before and after it and found that it no longer cleans well enough. Bank 2 is the side of a V engine without cylinder 1.
What you may notice
- Engine light on
- Emissions fail the inspection
- Sometimes a rotten-egg smell
- Less power if it's blocked
What could be wrong
- 1Old or damaged catalytic converter · Catalytic converter replacement €450–900
- 2Faulty rear oxygen sensor · Oxygen sensor replacement €90–180
- 3Exhaust leak · Leak check and hose or gasket replacement €60–120
- 4Misfires or oil burning have ruined the converter · DPF cleaning €200–400
Repair difficulty: Moderate
What you can check yourself
Before replacing an expensive converter, have the oxygen sensors and exhaust leaks checked. That often saves hundreds of euros. Best left to a workshop. It needs a diagnostic tool and experience.
How we fix it
- We compare both oxygen sensor readings
- We check for exhaust leaks
- We fix the cause of misfires or oil burning
- We replace the converter only when everything else checks out
Standard SAE description: Heated Catalyst Efficiency Below Threshold (Bank 2)