Catalyst: common defects and their signs

1. Soiling.
   • Engine power is reduced, the car accelerates hard. Sometimes these signs are accompanied by fuel consumption increase.
   • If the catalyst is fully clogged the car can fail to start or stall immediately.
   • Reduced emissions coming from the exhaust pipe.
   • «Check Engine» signal appears on the dashboard.
2. Melting or damage.
   • Rattling sound from under the car bottom is heard.
   • Exhaust gases have a bluish-grey colour and rotten egg smell.
   • Fuel consumption increased significantly.

How to replace catalyst?

If the catalyst is out of order it should be replaced because this element cannot be taken apart and repaired. The process will be different depending on the mounting location. It can be located either on the exhaust manifold (thus the exhaust manifold should be removed for catalyst replacement), or under the car bottom (thus the entire exhaust system would need to be demounted before component replacement). Anyhow, you should entrust replacement to service station specialists because special equipment is required for correct component installation.