Okay I'm going to put my law abiding citizen hat on for just a few minutes.

I can never find a straight answer on this and would appriciate if someone could help to clear the ground.

My understanding is that fitting a downpipe and having both cats removed is (A) Illegal (B) Will void insurance claims (C) will fail a MOT.

This is because any car from 1991 onwards requires to have at least one CAT. True of False ?

If I was to remove just one of the Cats, would it pass the MOT legal requirements ? , Would my insurance be valid if I made them aware of the power increase? , Would I not be breaking the law as long as my emmision levels were with the %3.5 CO legal requirement.
True of False ?


Okay taking my law abiding citzen hat off now and giving it back to my Granny.

looking forward to your comments

Maddy

Maddy, you are correct. The car must have a cat on to pass the emission test, be it a sport cat or a normal cat.

Not sure about the insurance being void as you would hold a valid MOT Cert, anyone?

By law you must be able to pass an emissions test. There's nowt to say that you can't meet the required level without a cat. If you could then it ain't illegal.
Summary - cats are not required by law :p

CATs ARE required by law on post early '90s (1991 I think) engines.

http://216.40.249.192/s/cwm/cwm/lurk.gif

I'm just gonig by the conclusion of a thread ages ago.
I'm off for a search :D

so which is it?

must you have at least one cat or is it only emission related?

anyone got a reference they can give to relevant legislation?

All it says on the ministry of transport page is that a car must meet the required emissions level.

CATs became law in the early 90's. If your engine came with one attached, you need 1 to pass MOT.

If your car came with 3 and you remove 2, I don't know what the legal view is. I would go to the MOT station who will be testing your car and ask them.

Interestingly if you have a 2000 car with a pre-early 90's engine, then it doesn't need a CAT.

Since 1993,European law has required that catalytic converters be fitted to all new cars

You must have at least one fitted to a post 91 engined car.

A valid MOT is not a staement to your cars road worthiness. Insurance require a car to be road worthy. This means they require maintenance to be continually carried out as required not once a year. An MOT is a snap shot in time in an attempt to catch a bad car and take it off the road everynow and again. It is not a representation of a cars legal right to be on the road. Hence if you crash and they find you car has an illegal area, missing cat, not due to unknown wear and tear you will be screwed. Your insurance will screw you given half a chance.

[Edited by dosenöffner - 30/07/2003 14:06:19]

Half right. Insurance and MOT are not related. However, just because your car is illegal, doesn't mean your insurance is automatically invalid. If that was so, then anyone with a failed brake light bulb would be driving without insurance.

If you don't tell them about mods, they have a chance to wriggle out. And if your car is in a "unroadworthy" condition - ie more likely to have an accident because something isn't how it should be - then you also might not be covered. But I don't reckon they could claim that not having a cat made you more likely to have an accident.

I'm not a lawyer...

This is an important subject to me as I've just had a new exhaust fitted and it doesn't have those bulgy things in it any more (and it sounds awesome)

As I understand it:

A scooby will pass the MoT with only the downpipe cat provided it is very hot

It will of course fail the MoT without any cats

It is not legal to drive around without them, breaking emissions laws, but I'm not sure anyone has yet been stopped and tested. I may be wrong, does anyone know?

IF you are stopped, you have a legal right to request a deferred test (because you had just suspected the exhaust may need some attention). At that test, the cats will be in place....

At scheduled MOT time, you make sure that sufficient cats are in place to pass.

I've done a bit more research and this is my understanding now, Something I did'nt realise is that my impreza has 3 cats, Cat 3 shown in the back of a fag packet diagram below was removed as part of the prodrive peformance upgrade.

Cat |2| I presume could be removed as part of a downpipe upgrade thus keep cat |1| which is a legal requirment and should be sufficiant enough to be within tolarance of road legal emmisions.

Diagram 0.2 (fag packet)

BACKBOX|3|=======MID SECTION======|2|--Downpipe--|1|



If i'm talking b0llocks then please correct me :P

Maddy

Now as far as I know the law states that all cars produced after 1991 had to be factory fitted with a CAT. But, If you remove the CAT then the car must pass an MOT emissions test without it for it to be legally drivable.Passing an emissions test with a CAT fitted and then removing it voids any guarentee of road worthiness

Why would you remove a CAT? Performance? Hmmmm. Insurance would want to know.

It should also be said that the cat needs to be in working condition. They do need replacing every 50,000 miles or so.

Can anyone explian the different emissions test for a Japanese import to me? They stick a pipe right into the exhaust but for UK cars they are allowed to just test from the end.

Could be worse. NZ has no emission rules currently but are introducing a law saying exhausts are to be no louder than the factory system. No, and I mean no, Subaru in NZ still has a factory exhaust fitted. There's a market to import them now. It is creating quite a few waves as it is at the testers discretion. The old system said you could do anything as long as it was under 90dB. That way it was measureable and now it isn't. Police can stop and order a check anytime and the bill comes out of your pocket whether they are right or wrong. Now that sucks.

[Edited by dosenöffner - 30/07/2003 16:13:15]

I have a single sports free flow cat in the centre pipe and it passes the emissions test very easily. Just need the Lambda sensor to be in good condition.

Les :)

To be safe you could fit a downpipe with a High Flow Cat. Does the same as the standard CAT but has a lower DP across it so a less restricted flow but still removes the emmissions in the normal way

These are available and from what I have experienced don't detrement power that much compared to full de Cat.

A sports CAT or high flow CAT is part of the STI8 PPP