Legally of decat pipe between MOTs

[Greengecko]

Hello,

Can't find to seem any exact information on this. I understand the cat is required for the MOT or it will fail, however I cannot find anything that says you are not able to remove this in-between MOTs - ideally I would like to fit a decat pipe as it is a 2.5L Turbo, however it is a 2007 car.

The insurance is declared as having a fully modified exhaust system.

Thanks

[snapdragon69]

Can't you make it look like it has one, such as by having a hollow one?
The MOT Tester's handbook says if you are not sure, assume it has one.

[Greengecko]

I have the CAT and would change these over before taking it to the MOT, that's not an issue.

My question is if you are legally allow to change the CAT to a de-CAT pipe between MOTs?

[kambites]

Greengecko said:

My question is if you are legally allow to change the CAT to a de-CAT pipe between MOTs?

Pretty sure you're not. I think it's illegal to drive a car that would fail an MoT on the road (happy to be proven wrong, though).

[rigga]

Legally no, if its post 92 and as standard it has a cat fitted then it must be retained.

Has nothing to do with what folks do though does it? Only a roadside check that might discover its been removed will cause an issue.

[supersingle]

It's only illegal if you get caught.

[Greengecko]

Thanks for the replies, I know quite a lot of people do it and can't say I've ever heard of anyone having any issues even when stopped but wanted to check the legality.

Lets say for example you were stopped and it was found a de-cat pipe was in use, what would be the worst potential consequence, if they were having a bad day and all.

[DanielJames]

Greengecko said:

Thanks for the replies, I know quite a lot of people do it and can't say I've ever heard of anyone having any issues even when stopped but wanted to check the legality.

Lets say for example you were stopped and it was found a de-cat pipe was in use, what would be the worst potential consequence, if they were having a bad day and all.

They might give you an MOT retest order, so you have to go get the car tested again. Had that with my tyres once

Chances of them pulling you, and saying you have a decat, are about 0.0000000000000000001% though

[BRMMA]

is there a massive difference in benefit of a full decat over say 200 cell sports cats? i'm sure a full decat is better but worth the hassle?

[mattball]

Pretty sure the worst that would happen would just be that they'd tell you to change it. Not really worth the hassle of them doing much else to you is there? Not quite like bald tyres or brakes in a terrible state.

[SuperchargedVR6]

If you're that worried, why take the risk? What car is it? Are the gains worth it?

On some cars, removing the cat/s actually reduces the bottom end torque.

Any copper who knows engines will smell your lack of a cat immediately.

[kambites]

BRMMA said:

is there a massive difference in benefit of a full decat over say 200 cell sports cats? i'm sure a full decat is better but worth the hassle?

I think that depends massively on the car and the purpose of the modification.

[Greengecko]

SuperchargedVR6 said:

If you're that worried, why take the risk? What car is it? Are the gains worth it?

On some cars, removing the cars actually reduces the bottom end torque.

Any copper who knows engines will smell your lack of a cat immediately.

Not worried, more interested as couldn't find an exact answer anywhere, and is nice to know what could possibly happen if it was stopped and pointed out.

Car is a Focus ST MK2, and does have considerable gains as the CAT is particularly restrictive on these.

[JonnyFive]

Just do it.

They'll just tell you to put one back in, and thats only if you get stopped at a VOSA stop check.. How often are they on the road?

[Garlick]

I pop mine back in before the MOT. Simple.

[Si_man306]

The chances of being pulled and done for a decat are as above, 0.0000001% but getting found out that it was on the car in an accident/ write off makes your car non-MOT worthy at the time of the incident and i'd be interested if anyone knew of any insurers who have had issues?

I had one and it was awful- buzzy as hell and unless you're running a high boost jap race car or something completely pointless as it ruins the low end torque- which on the road is 90% of what power you're using.

[Si_man306]

SuperchargedVR6 said:

Any copper who knows engines will smell your lack of a cat immediately.

Never actually met one of those!

[otolith]

If you get a roadside emissions test from VOSA;

"What happens when a vehicle fails a roadside test?"

http://www.dft.gov.uk/vosa/publications/businessli...

VOSA said:

If your vehicle is found to be exceeding the limits at a roadside test, you will be given a prohibition notice. This notice will usually not take effect straightaway, giving you time to have the vehicle repaired. Download a prohibition notice example from the VOSA website (PDF, 66K).

If your vehicle is seriously in breach of the legal emission limits, the date the notice will come into effect immediately. You will not be able to use the vehicle once the notice has been issued.

If other defects are also found which make your vehicle dangerous for further use then you may not be allowed to continue with your journey until the defects are fixed, or other arrangements are made for the vehicle's safe removal.

You will need to have cleared the prohibition within 14 days or you will be prosecuted. For more information on prohibition notices, see our guide on roadside prohibitions for vehicle drivers.

Where vehicles are found to be seriously in breach of the emission limits or other road safety critical defects, you are likely to be prosecuted as well as being issued with a prohibition notice with a further requirement to rectify any faults found.

Local authorities are also empowered to carry out roadside emissions tests in air quality management areas, and can fine you a £60 fixed penalty.

[Greengecko]

otolith said:

Local authorities are also empowered to carry out roadside emissions tests in air quality management areas, and can fine you a £60 fixed penalty.

Thanks for that, is much appreciated.

Not overly concerned, as long as there are no points involved and I have a chance to put the CAT back on. Live somewhat out in the country and rarely see a police car, let alone a VOSA test or similar!

[scott15]

I would just fit it. Ive never had any problem with 8 of the cars ive now had with either a decat, or not a full exhaust system.

Also in the event of a crash and insurance getting involved, that also doesn't seem to be much of an issue. A friend of mine had his car written off after having a head on collision. He had a decat pipe, and no backbox, Police or Insurance had nothing to say about this at all. Probably didn't even notice it didn't have one.