Catalytic Converters - martin
I was wondering if someone can tell me about Catalytic converters. What exactly do they do? What cars have them? What does the law say about them? When did they first appear?

I have a VW Passat TDI M Reg Estate, would this have a Catalytic converter and if so where this would be indicated?

Many thanks

Catalytic Converters - Dynamic Dave
I was wondering if someone can tell me about Catalytic converters.

Here's a starting point.
Catalytic Converters - Andrew Moorey (Tune-Up)
Yes your Passat does have a catalytic (oxidising) converter. It is about 6" diameter x 8" long in the first part of the exhaust system.

Happiness is a T70 at full chat!
Catalytic Converters - mal
I must have led a sheltered life on the internet,I never knew such an excellent site existed.

Now I know how a differential works!.

Thanks Dave.
Catalytic Converters - Dynamic Dave

I also didn't know the howstuffworks site existed until someone else posted it on here.
Catalytic Converters - Dwight Van Driver

Steer your way also to:

Click on the blue emissions.

Catalytic Converters - stefanta
I know that if they\'re fitted they have to be used. my mate used to take his off, and re fit it, when he took his cavalier in for a M.O.T , that way it would never burn out so it never had to be replaced, he got a bit more power out of the cav as well. but i know that its illegal, to remove them or should i say use a car without them if there fitted.....but who checks????
Catalytic Converters - SpamCan61 {P}
I'm fairly sure there's nothing 'illegal' about running without the CAT fitted. The only MOT requirement is to pass the appropriate emissions test. I'm sure I've read on this site of people sucessfully removing the CAT from 2 litre Carlton / cavliers and still passing the MOT. It doesn't help when the emissions test is known as the 'CAT' test....
Catalytic Converters - Andrew-T
As I understand it, a cat is a 'requirement' for all petrol cars with K-reg. or later. Just how 'legal' this requirement is, is another question which I can't answer.
Catalytic Converters - John S

This issue of still passing the MOT with the cat removed probably relates to early '90s cars where the cats were being introduced. In the case of the Cavaliers, and some models had them and others didn't. 2.0litres were a case in point - around '92 SRis didn't have them, but other 2.0 litre models did.

The result was that rather try to define the emissions levels to individual models, the emission levels were set for the non-cat cars.

It wasn't just Cavaliers. I had a '90 BMW with the optional cat, but the MOT pass level was that for a non-cat car.


John S
Catalytic Converters - Cliff Pope
Do they burn out? Mine's done 275,000 miles. I should have thought the short annual trip to the MOT would do it more harm than a year at proper operating temperature.
Catalytic Converters - Andrew-T
If it is a true 'catalyst' it should remain unchanged throughout its life if it's not subjected to conditions outside the design spec. The familiar problems are poisoning from impurities such as lead in Regular petrol, and break-up of the ceramic support by impacts with speed bumps, etc.
Catalytic Converters - SpamCan61 {P}
the bobmckay link above does point out you don't need a catalytic to pass the 'CAT' test; even on post 'K' reg. cars.

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