HI Andrew

I'm with Pete, classic c__p after market Cat.

Idle readings could be a little better but I would say just down to age of vehicle.

It's worth remembering that the Lambda reading is calculated value from other gases and (in theory) is the same irrespective of if the cat is working or not.

Have a look at this http://pwrautomotive.com/lambda.htm

As a general rule if the lambda reading are good but HC & Co are high it indicates a Cat fault.

The biggest problem with lambda readings are that it relies heavily on o2 reading so any leaks will cause incorrect calculated value. this needs to be remembered when relying on it for diagnosis.

Of course if it is a down stream cat it is simple enough to drill a test port pre cat

cheers aidan