Join Date: Feb 2010
Location: United Kingdom
County: East Riding of Yorkshire
When people say about warming the cat up on a run, it doesn't get that warm in just 10 mins.
Sit round the corner from the mot station with the engine at about 4,500 rpm for about 5 minutes, or if you do go for a run make sure its 3rd gear and about 4,500 rpm. That will really purge the cat.
However, from the readings you got i don't think it just needs a blast. I think you might have other issues. I could be wrong though.
P.S Changing the oil as ALFAPASH says is also a good idea. Oil gets petrol washed just doing small journeys, and as such there are extra UNWANTED petrol vapours that get into the combustion process.