What are the signs of a clogged catalytic converter in a Mercedes-Benz E-Class?

Home > Gari Forums > Mercedes Benz Forums > Mercedes Benz E Class Forums > Mercedes Benz E Class Catalytic Converter Issues Forums

Post a New Topic

What are the signs of a clogged catalytic converter in a Mercedes-Benz E-Class?

My Mercedes-Benz E-Class feels sluggish, and I’ve noticed a in fuel efficiency. Could this be due to a clogged catalytic converter? What are the common symptoms of catalytic converter blockage in these cars, and how can I confirm if it’s the cause of the problem?

Talha Kyanii asked on 11 Oct 2025 13:44:21 pm

1 Answer

11 views |

Gari Master - on 11 Oct 2025 13:45:21 pm

A clogged catalytic converter restricts exhaust flow, which can cause several performance issues in your E-Class. Common signs include:

Reduced Engine Power: The car may feel sluggish o r struggle to accelerate, especially at higher speeds.

Poor Fuel Efficiency: The engine uses more fuel as it struggles to push exhaust gases through the clogged converter.

Rattling Noise: A metallic rattle from underneath the car can indicate a broken o r damaged converter.

Overheating: A blocked converter can cause excessive engine heat and even damage nearby components.

Check Engine Light CEL: The oxygen sensors detect abnormal exhaust readings and trigger the CEL.

What to Do:
Have a mechanic run a diagnostic scan and check the exhaust backpressure o r temperature readings before and after the converter. If clogged, it may need cleaning o r replacement.