A couple of months ago I put the Octy into the dealers to find out why the CEL light had come on. It was still under warranty. They hooked up their computer and told me that the fault was "catalyst reduced efficiency" or words to that effect. They cleared the fault, but told me to contact the suppliers of the cat (Milltek) as it was faulty.

The light came on again a few weeks ago, so as the warranty has now expired I put it in to Jim Curley at Star Performance (who fitted the cat).

Jim hooked the car up to VAG-COM. Three fault codes showed up - the cat efficiency one, but also that both front and rear Lambda probes were faulty!

Jim told me that if the front probe is faulty, this will produce the fault codes that the rear probe is faulty and that the efficiency of the cat is down.

That being the case, should the dealer have picked this up two months ago and fixed it under warranty? And will I have to pay for it now? :mad:

You could certainly approach them. Do you have a print of the VAG-COM report and if so does it have timestamp info?