Gutting catalytic converter

On Fri, 28 Jan 2005 wrote:

> >It's just as illegal to remove a converter on a car originally so
> >equipped in the UK as it is in the US...and Canada...and the European
> >Union...and Australia...and Japan.
>
> One exception I know of is for 1975 and 1976 VW Golfs made for the US
> market. The rate of converter failures was so high that VW issued a TSB
> instructing mechanics to gut it and make some changes to the carburetor
> and EGR system.

Cases like this are *exceptionally* rare, and the new configuration is put
through Federal emission certification tests (multiple-day,
multiple-thousand-dollar series of tests) before it's OK'd for street use.

In article >, HLS wrote:

>> But, to answer your question: You will not gain anything by gutting the
>> converter.
>
> A convertor will add some backpressure. In theory, the more back pressure
> you remove, the better it might be able to perform. In practise, however,
> the gains for this type of 'modification' are next to nothing for the
> ordinary driver and ordinary engine.

If the OP is driving a 1970s vehicle then he could replace the catalyst
with a modern one and get the benefit he is looking for by gutting it. If
he is driving anything made within the last 15 years or so, then gutting
the catalyst will likely do more harm than good unless coupled with with a
bunch of other engine changes.

"Daniel J. Stern" > wrote in message
n.umich.edu...
> On Fri, 28 Jan 2005, Mark W wrote:
>
>> I live in the UK where my vehicle doesn't legally need a converter.
>
> Wrongo, check your laws again. It's just as illegal to remove a converter
> on a car originally so equipped in the UK as it is in the US...and
> Canada...and the European Union...and Australia...and Japan.
>
> But, to answer your question: You will not gain anything by gutting the
> converter.

OK - that's what I was wondering. But - if I decide to buy a decat pipe, I
think I might try gutting the converter first anyway, just to prove the
point to myself.
(And, I repeat that it's fine for me to do this on my particular vehicle,
although generally not on others)

On Sat, 29 Jan 2005, Mark W wrote:

> > But, to answer your question: You will not gain anything by gutting
> > the converter.

> OK - that's what I was wondering. But - if I decide to buy a decat pipe,
> I think I might try gutting the converter first anyway, just to prove
> the point to myself.

Please keep in mind that everyone must breathe what comes out of your
car's tailpipe.

"Mark W" <s@o> wrote in message
...
>
> "Daniel J. Stern" > wrote in message
> n.umich.edu...
>> On Fri, 28 Jan 2005, Mark W wrote:
>>
>>> I live in the UK where my vehicle doesn't legally need a converter.
>>
>> Wrongo, check your laws again. It's just as illegal to remove a converter
>> on a car originally so equipped in the UK as it is in the US...and
>> Canada...and the European Union...and Australia...and Japan.
>>
>> But, to answer your question: You will not gain anything by gutting the
>> converter.
>
> OK - that's what I was wondering. But - if I decide to buy a decat pipe, I
> think I might try gutting the converter first anyway, just to prove the
> point to myself.
> (And, I repeat that it's fine for me to do this on my particular vehicle,
> although generally not on others)

There's another problem in removing the catcon - the thing generates some
backpressure, and the replacement pipe won't so you may have some
driveability issues.

Is that the very same UK that is always bitching about how short
(<15-20km) oil change intervals in the US are screwing up the ecology?

Inquiring minds, and all that, you know......


"Mark W" <s@o> wrote in message
...
|
| "KENG" > wrote in message
| . com...
| > Depends, can you afford the $50,000 fine?
| >
| >
|
| I live in the UK where my vehicle doesn't legally need a converter.
|
| So, I was wondering how the gas flow through an open chamber compares
with
| the gas flow through a chamber filled with converter filling?
| I know the open chamber will not be as good for gas flow as a straight
pipe.
| Nor is a space filled with a honeycomb type filling.
|
|

On Mon, 31 Jan 2005, spare-me-spam wrote:

> Is that the very same UK that is always bitching about how short
> (<15-20km) oil change intervals in the US are screwing up the ecology?

The very same UK. They also jumped halfassedly and belatedly onto the
emission control bandwagon, requiring catalytic converters on all new cars
in *1991* and _mostly_ taking leaded auto fuel off the market in 2000. Oh,
and publishing all kinds of propaganda about how diesels are far cleaner
and their exhaust less deleterious to health, and taxing their fuels to
match this propaganda, until it was discovered (Whoops!) that they were
wrong. When that discovery was made, they carried on as though nothing had
happened, still babbling about how much cleaner/safer/better diesels
are...

Anyone who's been a pedestrian in London vs. New York knows they're full
of ****.

On Sun, 30 Jan 2005, Bob M. wrote:

> There's another problem in removing the catcon - the thing generates
> some backpressure, and the replacement pipe won't so you may have some
> driveability issues.

A lot of people don't understand this. They think, incorrectly, that ANY
amount of backpressure is necessarily a bad thing, and that ANY reduction
in backpressure will necessarily improve (pick one or more) performance,
economy, driveability, their sex life.

"Daniel J. Stern" > wrote in message
n.umich.edu...
> On Mon, 31 Jan 2005, spare-me-spam wrote:
>
> > Is that the very same UK that is always bitching about how short
> > (<15-20km) oil change intervals in the US are screwing up the ecology?
>
> The very same UK. They also jumped halfassedly and belatedly onto the
> emission control bandwagon, requiring catalytic converters on all new cars
> in *1991* and _mostly_ taking leaded auto fuel off the market in 2000. Oh,
> and publishing all kinds of propaganda about how diesels are far cleaner
> and their exhaust less deleterious to health, and taxing their fuels to
> match this propaganda, until it was discovered (Whoops!) that they were
> wrong. When that discovery was made, they carried on as though nothing had
> happened, still babbling about how much cleaner/safer/better diesels
> are...
>
> Anyone who's been a pedestrian in London vs. New York knows they're full
> of ****.
>

Well, actually the thing is that there's fewer cars and car owners in London
than
in New York, so it kind of evens out.

Ted