Hi, got a 307 xsi, had a cold start to the morning here, engine spluttered and took a few attempts to start it. When finally running I got the "Catalytic Convertor" & "Anti Pollution" warning message. Followed some other advice from the forum and drove hard and fast for 30 mins. The alarm was going off all the way until switching engine off. Once restarted I just have a single message "Catalytic Convertor Fault" beeps only once and then just the little fault symbol between the speedo and the rev counter. Is this really an issue? Or has anyone experienced something similar? Will try battery unplugging meantime.

James, Oxford, December 2011

Probably the lambda sensor is choked up after all the unburnt fuel that will have entered the exhaust with your problematic cold start.

You may find that it will clear after a long hot run but if not you may need a new lambda sensor fitting to replace the existing one.

ChicksFan, December 2011