What are the symptoms of a clogged catalytic converter in a BMW 2 Series?

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What are the symptoms of a clogged catalytic converter in a BMW 2 Series?

I feel my BMW 2 Series has lost power, and the fuel consumption has increased. A mechanic suggested that the catalytic converter might be clogged. What are the signs of a failing o r blocked catalytic converter?

Garitips asked on 19 Feb 2025 15:12:39 pm

1 Answer

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Garitips - on 19 Feb 2025 15:20:38 pm

A clogged catalytic converter can severely affect your BMW 2 Series’ performance. Here are the signs:

Reduced Engine Power: If the exhaust flow is restricted, acceleration becomes sluggish.
Poor Fuel Economy: A blocked converter forces the engine to work harder, increasing fuel consumption.
Rattling Noise: If the ceramic honeycomb inside the converter breaks down, you may hear a rattling sound from the exhaust.
Overheating Engine: A clogged converter traps heat, causing the engine to overheat.
Sulfur Rotten Egg Smell: This smell indicates excessive unburnt fuel in the converter.
Check Engine Light CEL: Codes like P0420 Catalyst System Efficiency Below Threshold appear when the converter isnt working properly.
Solution:

Use a catalytic converter cleaner in the fuel tank to dissolve minor clogs.
Get an exhaust backpressure test to confirm if the converter is blocked.
If severely clogged, replacement is the only option.