chrisyd

anybody know what causes a cat converter to become blocked, mine is, reducing my gas flow, resulting in reduced power. been running the car on regular unleaded so cant figure out why ?

BugEyed

Blocked cats can be from a number of sources, but the most common are overheating and oil ingestion. Overheating is generally caused by a fuel or ignition system problem - you will probably have noticed the symptoms of this and fixed the other problem without realising that the cat is damaged. Oil ingestion is normally caused by overfilling the sump or having excessive blow-by on the rings causing the engine to "breathe" heavily pushing oil into the intake. Again you should have been aware of this.

You mentioned that you have been running "ordinary unleaded". It is possible that your exhaust gas temps have been too high as a result of this causing the cat to fail.

Duncan

chrisyd

cheers for info mate, well appreciated.