De-Cat Emissions

blazedoobie · Dec 9, 2004

Ok

Who on here has a decat pipe, what year and have you passed the emissions test with the decat in place?

I want to rid myself of the cat, but dont want to fanny about every year with re fitting the cat and i am not paying the extortionate prices that are being charged for a 'sports' cat.

So if anyone has done this a passed raise your hands!

The Walrus · Dec 9, 2004

I have the decat pipe but my MOT wont be up until May, sticking my neck out I am 100% sure it will pass emissions as it is a very clean engine.

If you can find a friendly MOT bay where they would let just check emissions for a few quid would be your best bet.

evilhomer · Dec 9, 2004

Somebody show the legislation that states it is only the emmisions that are important again... the only law abot the cat was that it had to be fitted to all new cars by law after 1992 I think. (But that was just to control emmisions.)

admittedly there are gonna be some MOT testing stations that push it, to try and lmake life difficult... get friendly with one!!![

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Mr Benn · Dec 10, 2004

AFAIK, there is no law about having to have a CAT. The maximum emissions that the engine is allowed to produce is determined by the year that the car was homologated. I don't think any manufacturer has been able to meet the emission requirements without having a Cat fitted. These are a considerable expense to the manufacturer and they wouldn't fit them if they didn't have to. I think if you had a car from the early 90s then you could get away with no Cat if you could just run the engine lean at idle. It wouldn't make any CO or HC, just NOx which they don't test for on that age car. They do test for it no and I don't think you could meet the requirement without a Cat but you could certainly try. Some friendly MOT test places may allow you to drive around for a bit to get the engine hotter if you think that will help.

evilhomer · Dec 10, 2004

Quote: posted by Mr Benn on 10/12/2004 15:46:30

AFAIK, there is no law about having to have a CAT. The maximum emissions that the engine is allowed to produce is determined by the year that the car was homologated. I don't think any manufacturer has been able to meet the emission requirements without having a Cat fitted. These are a considerable expense to the manufacturer and they wouldn't fit them if they didn't have to. I think if you had a car from the early 90s then you could get away with no Cat if you could just run the engine lean at idle. It wouldn't make any CO or HC, just NOx which they don't test for on that age car. They do test for it no and I don't think you could meet the requirement without a Cat but you could certainly try. Some friendly MOT test places may allow you to drive around for a bit to get the engine hotter if you think that will help.

I honestly think you will be surprised... I have a number of friends who have been through this, with modern cars varying from Saxo VTS's through to 6 cylinder Beemers. All past the emissions tests...! The modern engine is pretty damn efficient methinks... Am hoping I will get away with it myself soon. [

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ollie · Dec 11, 2004

i`ve got a de cat pipe bazedoobie and i`m going to get my mate to check the level cause he works at a test centre

GaryM · Dec 11, 2004

Im having a decat fitted this Friday then I'll take it past an MOT centre when I get chance and see if they will check emmissions.

evilhomer · Dec 11, 2004

Great, will be nice to get a rough idea... I know that the V6 is gonna be more havy duty on emmisions but then again your all revo'd up to the nines so may not be too far off!![

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thechief · Dec 11, 2004

Theres plenty of ways of getting round the emissions test if your friendly with the tester [

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GaryM · Dec 11, 2004

I believe one being get the cat nice and hot before the test.

vedhead · Dec 11, 2004

If you dont have a CAT you wont pass an MOT.

GaryM · Dec 11, 2004

Quote: posted by vedhead on 11/12/2004 21:08:32

If you dont have a CAT you wont pass an MOT.

Even if the car still passes the emmissions test?

evilhomer · Dec 11, 2004

Quote: posted by vedhead on 11/12/2004 21:08:32

If you dont have a CAT you wont pass an MOT.

There is no law or legislation that says you have to have one on... it's just emmission levels. Are you diagreeing with that, or are you just saying you don't think the emmision levels will be low enough?

ollie · Dec 12, 2004

i think he`s saying that the emmissions won`t be low enough. has anybody been thru the mot with a de cat?

blazedoobie · Dec 12, 2004

dudes, thanks for the response. I am friendly with an mot tester, and he lets most non critical things off, but tyres and emissions he is hot on. Plus he tld me that emissions testing is to become tougher what with the mot being linked to some central govt database / test rig.

GaryM / Ollie it will be good to see the results of the tests!

blazedoobie · Dec 13, 2004

bump

(although i have my eye on a ghl dp with cat for about ?150 plus shipping...)

morse · Dec 14, 2004

I still have my cat with my milltek cat back and was in for my MOT last Saturday (at my friendly MOT tester). In years gone by I had often been let off the emissions test all together if the computer didn't start etc but this year was different. He had a new more accurate computer to do the testing and mine had to be done three times (with long runs in between to get the cat hotter) before it passed. There was an issue with the lambda emissions and I eventually got it within .004 of the acceptable limit. Was told that my cat was probably on the way out. I can't see how I would have passed without a cat though, but I'm no expert...

blazedoobie · Dec 14, 2004

thanks for the input morse. This is what i was fearing, the new tougher MOT emissions test.

3 runs, damn...i bet there will be alot of people having to do that many runs. Especially if you have waited and everything has cooled down!

btw .004 of what? HC's?

morse · Dec 14, 2004

Blaze,

It was measured for three things: CO, HC and Lambda. I have no idea what Lambda is (I know there is a Lmabda probe on the car). CO was a % and HC was measured in ppm (parts per million) but there was no quantity measurement for Lambda. I haven't got the printout with me but I was going to find out what this was all about.

I can't find any useful information on any government website. This explains what is tested but not what Lambda is...

(I know that if I took my car to a stealers for the MOT it would have cost me a lot of money as they would have failed me first time)

Gti Jazz Blue · Dec 14, 2004

I'm pretty sure that you will need to have the CAT in place to pass the emission test, unless the car details are incorrectly entered (i.e. for a non CAT car).

DVLA will be linked in soon as the plan will be for the old bill to be able to identify on a check - if a vehicle has Tax, insurance and a current MOT. Got to be the way forward and shouldn't be an issue for any of us legal drivers with Tax, MOT and insurrance. Anything to keep un-insurred drivers off the street is OK in my book.

De-Cat Emissions

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