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General => The garage => Topic started by: Cupra Turbo on 19 January 2004, 17:08

Title: De-Cat a Mk3 GTI 8v
Post by: Cupra Turbo on 19 January 2004, 17:08
If I De-Cat my 8v will it fail the emissions test?

Does the 8v NEED the cat? I heard some cars dont NEED it to pass the emissions test...
Title: Re:De-Cat a Mk3 GTI 8v
Post by: adyh on 20 January 2004, 10:27
Yes you wil fail the emmissions test .

The reason other cars can pass without one is due to the fact that they were built before manufacturers were forced to put them on every car .
Title: Re:De-Cat a Mk3 GTI 8v
Post by: richandhazel on 20 January 2004, 11:29
I was able to remove the one from my Audi but that is because its on an 'H' plate, 1991. I think its from April (or thereabouts) 1992, all vehicles must have a cat fitted and will be tested accordingly.
Title: Re:De-Cat a Mk3 GTI 8v
Post by: richandhazel on 20 January 2004, 11:34
Just looked in the MOT manual and it looks like its August 1992 onwards:-

http://www.motuk.co.uk/manual_730.htm

Title: Re:De-Cat a Mk3 GTI 8v
Post by: golfvr6 on 20 January 2004, 19:23
Yep that is correct, Aug 92 K reg onwards will require a cat. Rich is correct as ever  :-*
Title: Re:De-Cat a Mk3 GTI 8v
Post by: Cupra Turbo on 20 January 2004, 22:45
so de-catting will make my emissions too high?


I know lads who've de-catted their cars and they pass MOT's and sum have W Reg Scooby's and new Corsa's etc
Title: Re:De-Cat a Mk3 GTI 8v
Post by: golfvr6 on 20 January 2004, 23:16
August 92 onwards, a car MUST be fitted with a cat, it is illegal to use on the road if removed. Must be a dodgy MOT.
Title: Re:De-Cat a Mk3 GTI 8v
Post by: modulater on 20 January 2004, 23:35
Its common practice on vehicles after august '92 to fit the cat back on for MOT's and remove it the rest of the time and fit a bypass pipe.
 
If you get stopped for a random roadside emissions test I think you would be a bit screwed if your cat wasn't in place.
Title: Re:De-Cat a Mk3 GTI 8v
Post by: winstonb on 21 January 2004, 06:17
I there any point to removing the cat?  i know the idea is to remove a and obstacle to air flow, but does it actually improve performance noticably?  isnt the Lambda sensor inside the cat, so wouldnt removal mean the injection system cant adjust itself quite right?

sounds like too much trouble for being uninsured, which you definatly will be...
Title: Re:De-Cat a Mk3 GTI 8v
Post by: golfvr6 on 21 January 2004, 15:40
When changing the cat for a pipe , the lambda sensor will screw into that.
Title: Re:De-Cat a Mk3 GTI 8v
Post by: richandhazel on 21 January 2004, 16:01
I've still got my lambda sensor.......they cut the boss off the old cat and welded it to my new pipe.
Title: Re:De-Cat a Mk3 GTI 8v
Post by: Cupra Turbo on 21 January 2004, 16:25
Why do newer cars need cats? surely new engines are cleaner than those iron blocks that they used to use in the 80's etc...

i'd have thought if new cars needed em then odl cars definately should need em... i always see old E reg's etc puffing loadsa black smoke during gearchanges etc
Title: Re:De-Cat a Mk3 GTI 8v
Post by: golfvr6 on 22 January 2004, 00:02
Newer cars need cats to cut down on emissions, it makes no difference really, all engines in good condition burn fuel so will emit something, cats turn the harmful gases into water and harmless gases.
Theres no way any engine is going to produce under 0.5% co without a cat, this is the limit for the MOT.
Title: Re:De-Cat a Mk3 GTI 8v
Post by: Cupra Turbo on 22 January 2004, 23:29
and older cars dont require them cos they werent standard?

I think any old car that had a cat, shouldnt be allowed to remove it
Title: Re:De-Cat a Mk3 GTI 8v
Post by: golfvr6 on 23 January 2004, 00:09
The regulations for emissions are much more relaxed for cars registered before Aug 92.
Title: Re:De-Cat a Mk3 GTI 8v
Post by: Cupra Turbo on 23 January 2004, 12:55
they should chage the regulations then!  :-*
Title: Re:De-Cat a Mk3 GTI 8v
Post by: i-espedair on 23 January 2004, 16:04
But cats are expensive units and fitted to old cars they would seriously screw up an engine that wasn't designed for one meaning further expence.

They couldn't make everyone with an old car by and fit a cat. Would be ridiculous! ...But bloody funny... hang on... I don't have an old car...

... Yes lets change the regulations! Give all you mk2 owners something to moan about!
Title: Re:De-Cat a Mk3 GTI 8v
Post by: Cupra Turbo on 23 January 2004, 23:48
yeah, fit a cat to all those mk1/2's ... heh heh
Title: Re:De-Cat a Mk3 GTI 8v
Post by: Veedubgt18v on 23 January 2004, 23:53
you only want that to slow us down so you lardy arse mk3's dont feel left behind  :P
Title: Re:De-Cat a Mk3 GTI 8v
Post by: mk1 on 23 January 2004, 23:58
Putting a cat on a early car will produce more pollution than a correctly set up engine. To manufacture the cat causes a heap of bad stuff, just not in our back jard tho. Bit like having a electric car, the exhaust pipe is at the power station, not the back of the car. Cats were a product of the gummermint, not common sense. Gee, I have had a bad week >:(, must stop moaning.
Steve.
Title: Re:De-Cat a Mk3 GTI 8v
Post by: Cupra Turbo on 24 January 2004, 01:00
Quote
you only want that to slow us down so you lardy arse mk3's dont feel left behind  

shame the mk3 is an overall sexier car...

and the mk2 is about 0.000001 faster... the mk3 only weights a lil bit more and IIRC its got more power... just
Title: Re:De-Cat a Mk3 GTI 8v
Post by: Veedubgt18v on 24 January 2004, 10:10
still faster tho!  ;)  :P