Just to clarify, I don't mean for the MOT, I am assuming I will fail with a decat. But I would like to know if anyone has ever had any bother with the police, have you ever been pulled over and if so what did they say?
Also, for anyone unfortunate enough to have made an insurance claim, did a decat cause any issue?

Incidentally, I bloody love the sound with a decat. I have a super sprint cat back and a straight through decat pipe. Not too loud but a more defined growl when you open it up

I'm sure someone far more clued-up on the subject on here once said that, technically, you don't need a cat on a car. You just need to be able to pass the emissions test. Clearly a Coupe wouldn't pass it without one but the police cannot say that at the side of the road. The most they can do is insist that you go for another emissions test.

I may be talking total tosh (and so might the afforementioned FCCUK contributor) so take it with a spoon full of salt!

Again - purely anecdotally (ie this is MY understanding) - using a car on a public highway is a breach of Construction and Use regulations, and as such, is illegal

If you are stopped by a police officer, or a VOSA inspection, there could be implications (as a missing cat is a pre-meditated modification, as opposed to an inadvertent failing of an emissions test)

Not sure what the penalties are though

They occasionally do roadside VOSA/emmisions testing and if the car fails badly they'll prevent you driving it away, insisting it's towed for "repair". They also have the power to seize a vehicle in extreme cases.

Most likely you'll just have to present a valid MOT certificate at local police station within 7 or 14 days or whatever.

I did run a de-cat on my 1st coupe and it did sound and perform better, but was a pain in the ass come MoT time unless you know a very friendly tester.

I wouldn't run a de-cat now as not that bothered about small gains v's hassle + it does significantly shorten the life of the standard turbo.

I remember reading on a forum a few years ago (i think mondeo st)that people were smashing out the innards to leave a hollow pipe and would still appear to have a cat fitted!

But as GrahamL has stated is it really worth the hassle for a bit more and technically it would be a modification so i assume you would need to declare it on your insurance! to stay legal

As a matter of interest has there ever been a direct comparison on a car with and without a cat, on the same rolling road same day etc. would be interesting to see the results!

Not that I'm aware of but I should think at least 5% more power and a lot more throttle response. It's a huge restriction!

I was lucky enough with my last coupe to have a play with it de-catted in a test centre.
We found that if the car was very warm (from a good thrash, hot Turbo etc) the car would have passed its MOT. Once it cooled it was miles out.


So yes, cat required

Roy

Also, it's a fail if a car which should have had a cat fitted, hasn't - which is basically everything from 1993 or so.



Several; here's one: http://www.importtuner.com/features/0610impp_catalytic_converter_removal/viewall.html - for some reason, I'm suspicious of the comparisons displayed by the tuners, all of which seem to show significant improvements!

I've seen other magazine articles, again with the same insignificant differences.

Vosa have enough to do with lgv stop and checks, mostly on foreign trucks entering / leaving the uk.
It's far easier to make money from lorry drivers / owners than car drivers.
Truck fines for
Dog clip not engaged in fith wheel, fine
Tyres, fine / points
Lights, fine
Missing number plates, fine
Load security, fine
Weight, (truck not the driver lol) fine
Tachometer infringements, massive fines, points, prison

There's only prostitution that carries similar risks of going to prison than being a lorry driver.

So unless they are positively targeting cars, for example red diesel use we're pretty safe from roadside inspections and prohibition orders as car drivers.

And in other news, speed limits only apply when there is a risk of enforcement? </sarcasm>

Agree - my car came with a 2.7" decat system and I want to get legal preferably without loosing power. (See my thread here. )

However due to the current configuration on the car there seem to be no alternatives short of fitting a new exhaust system or hacking what's there, neither are cheap options and hacking it would ruin what must have been an expensive system.

Seems there are are plenty of ways to make the car illegal but not many to make it legal. I get the impression that most on this board would say "don't bother". !

IMHO anyone who runs a decat is mad. If you cause an injury or worse in an accident and your car is examined and shown to have no cat/performance enhancing mods, your insurance company can hang you out to dry. I would not like to be in court in that scenario.

John

Agree, stay legal and go with a race cat

Just wondering, how do you declare a non road legal mod to your insurance?

Can anyone point me in the direction of a decent race cat?

You don't do the mod.

Don't worry no plans to. But more of a question, how/can you insure a road car with an illegal mod?

Isn't a Race cat legal after all a "CAT" is well a "CAT" never seen anything that specifies a certain type of CAT!

Just as long as its capable of passing an emissions test it should be fine!?? shouldn't it?

It's not the Cat bit it's the road legal bit. If your car is not road legal then your insurance is null and void. If the car would pass emissions after the crash even with CAT removed then you will still have a hefty insurance bill for not declaring a modification, performance or otherwise.

Bear in mind that insurance companies don't pay out if
they can help it. If you have to refit a cat to get a car through
an MOT then removing it after the test must mean its then
no longer road legal and your insurance is then invalid.
In the event of an accident I think any insurance company
would state that your insurance was not valid even though lack of a cat wasn't a factor in the accident.
That means you would be persoinally liable for the costs associated with the accident. Not good

Unless the lack of a cat caused you to have more performance and increased the risk of an accident occurring, of course......

But supposing you've declared the cat removal to the insurance company and they've accepted by issuing you a policy. How does that then work? You're then at odds with the T+C's. Seems like a huge ache best avoided.

testing manual section 7.1 rfr 3 - You must have a CAT fit or you fail. By visual inspection, so technically you could have a dummy CAT, a map so your car runs lean at MOT test revs / under no load and pass emissions and be OK.
You can't dismantle a car for an MOT so they can't check if the item purporting to be a CAT is actually real.

But, as it makes your car un road worthy, you couldn't declare no CAT as a modification and legally drive on the road as you've just nulled* your MOT and hence your insurance.

*you can have OK tyres at MOT time, they can become illegal during the year and that would also invalidate your insurance.


Edit - LPG cars don't fail with the cat removed.

To add further fuel to the (catalysed) flame: though this doesn't affect *most* coupes, if the cat is replaced on a post 2001 car it *must* be replaced by a type approved part; you can't just stick any old cat on.

Just to confuse things even more...

Regardless of the age of your car, if you can prove that the engine fitted is from before than the year the requirement for a cat came in then you're ok.

So if you can find pre-cat lump from a Delta or similar then you could be legal without one... though unless you're short of an engine to start with (which I was) it's much easier to just run a cat!

Before reading the RFR the method of inspection shoukd always be read. The car can pass with no cat. We had this argument
With the vosa guy on our refresher course last
Week and if you read the methods of inspection first it
States that an emission check must be carried
Out before any refusal is given. If it passes the emssions then it should pass. Just becuase something isn't
There does not mean it won't pass

^^^ - fair point - my Coupe somehow got VERY close to passing the emissions test with no cat fitted - no idea how or why, but the examiner commented that it was extremely close