I contacted a (very) local garage to me today with regard to having my cat back exhaust sytem fitted and de-cat at the same time, to which I was met with a response of:-

"That would make the vehicle illegal to run sir, and you risk a £1k fine :cop: and I as the garage owner also risk being fined"

Said garage owner is one half of a local racing team who run a diesel golf so I am inclined to think he is aware of what he is talking about.

I know that people on this forum run de-cat systems and was curoius to know whether any of the de-catted owners had been advised of this apparent illegality?

:rubchin:

I think it is illegal to remove one if it was factory fit. I'm sure Phil (piv34uk) will know for sure as he's an MOT tester.

It was an interesting conversation as I contacted one or two places one of which deals in custom stainless exhuasts (with a higher than average Ch4v following judging by thier website gallery) and there was not even a hint from them upon enquiry that de-cats are/could be illegal.

its illegal on a petrol unless pre 1993, K reg!

as for diesels its okay upto 2001! after that its illegal!

Would imagine this would be the case on a Petrol vehicle but I was of the understanding that the cat did very little on a deisal, probably wrong, again

Would imagine this would be the case on a Petrol vehicle but I was of the understanding that the cat did very little on a deisal, probably wrong, again

I don't think it was a case of whether it "does" anything but more a case of whether it is illegal to run without a cat.

i have just given the answer dudes!

the reason diesels pre 2001 could get away with it is because diesels arent emmisions tested only smoke tested, also they brought in a new regulation for diesel cats then

I had a 306 hdi (2000) and it was fine to decat whereas another lad had a 2001 hdi and it would have failed

I don't think it was a case of whether it "does" anything but more a case of whether it is illegal to run without a cat.

And I was clarifying why i thought it would be the case on a petrol and not deisal, as the converter on a oil burner does nothing to reduce NOx, but on checking does convert monoxide to dioxide and Hydrocarbons to water.

Catalytic converter - Wikipedia, the free encyclopedia

i have just given the answer dudes!

the reason diesels pre 2001 could get away with it is because diesels arent emmisions tested only smoke tested, also they brought in a new regulation for diesel cats then

I had a 306 hdi (2000) and it was fine to decat whereas another lad had a 2001 hdi and it would have failed

Intersesting, one assumes that if you had a de-catted post 2001 diesel that went for an MOT that the tester would jack the car up and say "no cat = fail" as presumably if diesels are only smoke tested you would not be able to tell from this test alone?

Yeah if they just stuck the prong up the exhaust you wouldnt be able to tell, but im sure it will be on there checklists anyways!

just depends who you know, i can get my car through MOT's without cats, my dad got his evo 4 gsr through (4years ago) without CAT, was tested and failed on emmission so the tester prong just got stuck up a 1.0l fiesta, tester said "gosh that evo is running clean" lmao

Yeah if they just stuck the prong up the exhaust you wouldnt be able to tell, but im sure it will be on there checklists anyways!

just depends who you know, i can get my car through MOT's without cats, my dad got his evo 4 gsr through (4years ago) without CAT, was tested and failed on emmission so the tester prong just got stuck up a 1.0l fiesta, tester said "gosh that evo is running clean" lmao

Interesting :rubchin: I guess it comes down to the individual then at the end of the day as to whether or not they are prepared to run the risk either way.

/\ family friend, i doubt many would do it, if any!

so to wrap up

No CAT is okay if

A. Your me

B. Petrols before 1993

C. Diesels before 2001

I had a straight through pipe on my Ibiza PD 130 and it went straight from the down pipe through to the small backbox!

It passed the MOT with NO problems

It did have a bigger turbo though

i think the general rule with MOT is that if it passes the emissions then it passes.

without sounding rude to MOT testers are many of them even aware of what a sports cat is?

I thought that the illegality was in running a car that had illegal emissions, rather than in one that didn't have a cat?

I thought that the illegality was in running a car that had illegal emissions, rather than in one that didn't have a cat?

It's removing a part of the emissions control gear. In the same way that running your breathers VTA is also illegal, removing charcoal canisters etc.

The correct way to do it is to replace the part with a properly designed and tested aftermarket part. Be it EC, TUV or BSI approved...

In countries where visual inspection of emissions gear is carried out in roadside checks, it's not uncommon for people to "unblock" the exhaust by de-coring the cat, leaving a big hole in the middle.

J.

If your car passes an emissions test without a cat, then it's legal.

Diesels have no requirement to have a cat for mot test as long as they pass the smoke test

Petrol engines after 01st August 1992 have to have a cat emission test unless import/kit car or the like...up to 01/08/94 if it fails the basic emission test you then have to find the exact make model and engine code to do a specific test if this cant be found you go back to pre 1992 emission regs....From the 01/08/1994 again BET is used if this fails you then must use the specific or nearest info available to you:confused:

Diesels no requirement............

Petrols WILL need a cat to pass even 100cel ones fail:rolleyes:

You (or i ) could possibly fail the cat being missing under the exhaust section "part of the system missing or excessively deteriorated.....lol this i would think would be petty:P

By the way my red Octy vrs runs a 100cel, the black one is decatted:eek:

Phil