Cheers I will change the plugs,, the nice thing about an old car is at least most parts are easy to get to.

Thanks for all the help I've just ordered some single ground pin plugs from GSF I wish I didn't rush in and buy a new cat now as I've just seen I could of saved myself over £20 buying one through them.
Hopefully I should be driving the old girl again by about Thursday fingers crossed.

Thanks Steve
It does go to show the difference in quality when the original Audi cat lasted 19 years and the one I'm now replacing has only lasted just over a year and 4000 miles.
My other car is now 18 years old and that's on the original also.

When a new cat costs £60 but you can get the same off the scrap man for an old genuine one it's pretty certain that there's a difference

I put my details in the parts gateway looking for a secondhand cat but the only reply I got back was from a company called cat man hopefully it will be ok.
I guess one of the problems with my car is the last model with the same engine and exhaust etc as mine was built around 93/94 so there are not many second hand cats around in good nick.

Well the car went through the emissions at last so it has a nice new MOT
I took the car down to the local exhaust centre who were fantastic the only problem was that when they fitted the cat it was blowing as half the welds were missing.

So I had to take it to an engineering company over the road who welded the seams up for me.
I tried getting some money back from the company who supplied the cat for the welding but it seems the guarantee only lasts 5 minutes.

So if your after a CAT for your car don't use CAT man.

Well the guarantee for the cat lasted less than 5 minutes.
Kwik fit fitted it for me then called me over to show me that half the welds were missing so I informed the company I bought it from that now my car sounded like a tractor because of the crappy cat that was supplied to me.

So I called cat man about my cat and all I got was its now out of warranty and can't send it back now its been repaired.
I would of thought any company would of at least apologised and paid for the repair but at least I know never buy a cat from cat man who advertises on the parts gateway in future .

So I doubt it will be any good come next mot.

There is a huge amount of misinformation on here about your test results (only just seen this post).
A CO reading of between 0.50 and 0.70% is in almost all cases due to the CAT failing so long as the others are within limits.
In this case the HC was well within and the Lambda was perfect at 1.00 (forget the decimal point, it means absolutely nothing).
So the original garage were right when they said it was double the maximum.
Almost 2 years ago the EU tried to tighten up the rules on cheap Cats. Properly manufactured ones are now marked with the EU label. But, those from eastern Europe are still around, are still being sold and are virtually worthless. They will last a couple of weeks but you wont know this until the next emissions test.
As a very rough guide, if it costs less than £100 then it may not be the real deal.