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Model specific boards => Golf mk3 => Topic started by: carl on 31 January 2005, 16:03

Title: decat mk3 8v
Post by: carl on 31 January 2005, 16:03

i want to get rid of cat on my golf gti 8v 1997 with straight through pipe ,ive been told i will get 12bhp from doing this ,have i been advised right, there will be no problems with mot because my brothering law is mot tester,any bad storys with doing this mod will be appriesated,cheers

Title: Re: decat mk3 8v
Post by: mrwotto on 31 January 2005, 18:10

I would say that de catting your car will through the emmisions out and therefore would fail the MOT.

Title: Re: decat mk3 8v
Post by: Optimus Wol on 31 January 2005, 18:30

^^ your right. it'll show a very low lambda reading (i think...) and the CO emmisions will be right up. you will gain power though by having a straight throughpipe, as there would be no restriction in that part of the exhaust. 

Title: Re: decat mk3 8v
Post by: mrwotto on 31 January 2005, 18:52

i have heard about people just sticking the cat back in for mot's, but you will still run the risk of failing a road side emission test.

Title: Re: decat mk3 8v
Post by: Len on 31 January 2005, 20:53

Well your bro in law is a twit!

The ruling is if your car when originally built was fitted with a CAT then it MUST always have a CAT fitted for the MOT!
Anything else is Boll*cks!
Also as others have said it WILL fail on emmissions.

And as for getting 12 bhp - very doubtful.

Title: Re: decat mk3 8v
Post by: AudiA8Quattro on 01 February 2005, 00:26

August 1992 onwards, its compulsory to have a cat  :laugh:

Title: Re: decat mk3 8v
Post by: ridgers on 01 February 2005, 01:02

Quote from: carl on 31 January 2005, 16:03

i want to get rid of cat on my golf gti 8v 1997 with straight through pipe ,ive been told i will get 12bhp from doing this ,have i been advised right, there will be no problems with mot because my brothering law is mot tester,any bad storys with doing this mod will be appriesated,cheers

If your brother in law is an MOT tester then he will know that a car built after august '92 must have a cat fitted to it by law and wont go through an MOT without it.

You can fit a bypass pipe for the other 251 days of the year but run the risk of getting caught by a roadside emissions test which your car would no doubt fail without the cat in place.

Also seeing as I doubt you would get 12bhp by just replacing the cat on an 8V i think its a bit of a pointless exercse all round.

Title: Re: decat mk3 8v
Post by: mrwotto on 01 February 2005, 10:26

I always thought there was 365 days in a year :grin: :grin:

Title: Re: decat mk3 8v
Post by: J-man on 02 February 2005, 14:37

I used to run a de-cat on my Integra Type R and did make a difference in the performance (although 12 bhp is bit of a push) as well as making the HKS exhaust sound  :cool:

I would put the cat back on about a week before the MOT and it passed no problems then take it back off again. The chances of getting stopped for a road side test are very slim and if you did they would most likely issue you with a Vrec to get it road legal at which you put the cat back on.

I know a number of people with performance cars who have de-cats as the cat is quite restrictive but on an 8v Golf I don't think it is going to make that much difference to honest.

Up to you mate.