Re Cat's pause - 3rd September 2016

I had a similar problem to DH with a 2000 1.4 Fabia a few years ago. A fast motorway run followed by idling at an exit junction brought up a warning light followed by 'lumpy' running when pulling away. Filling up with higher octane petrol definitely cleared the problem.

Some time later the car began to run unevenly when started from cold. When the engine warmed up the symptoms always disappeared. The main dealer couldn't diagnose the problem so I contacted a local independent garage who cracked it in one go. At the time VW group garages used a diagnostic computer that gave less detail than the one used by my garage (yes I go to him whenever possible now!) but you need to be able to read the raw data on the screen.

My son now has the Fabia which only shows the original symptoms if normal unleaded is used. Super gives slightly higher MPG - proved over several months so the net extra cost is zero!

PS - That shows the difference between a factory trained mechanic and a talented motor engineer!