The existing cat is working but I get the immpression that it isn't big enough to cope with the volumn from the 2ltr engine. It has to be super hot to get close to the required levels. I am hoping that someone could tell me if the addition of an extra cat-con would solve the problem without having to rev the rocks out of the engine for half an hour.

OK. Thanks. Looks like I'll just have to bite the bullet and get a new one :-(... I have heard of a method of burning off any excess fuel from the cylinders. It involves a spark generator and special spark plug, similar to the system used in space heaters.This is fitted into the exhaust before the Lambra. Any thoughts about that.Thanks.

A clogged air filter won't make any difference on an injected car as far as emissions go.

If the lambda sensor is dirty or faulty, it'll crop up in your emissions test since lambda is estimated by the gas analyser.

There's no "excess fuel in the cylinders". If there was you'd have an HC problem as well as a CO probem. High CO with everything else ok points to a tired catalytic converter. The precious metals become sintered into the washcoat with age and the conversion efficiency drops.

The only 'bodge' is get the exhaust system really hot immediately prior to testing ie blasting the car up and down the road before they put the probe in the exhaust pipe. but if you have to wait a few minutes for the retest, it'll cool down-even if you leave it idling.