Decat a diesel

[Randomman]

Hi all, I know a lot of dervs fly through emissions without a cat/particle filter. Is the Cupra TDi one of these vehicles? A mapped one - obviously!

 

[ChrisUK]

Isn't that because diesels arn't tested for emissions at MOT ?

 

[mattyfab]

Aret diesels just tested for smoke??

 

[hon_n_gem]

Aret diesels just tested for smoke??

i think so...so we should all pass easily! only under heavy accereration do we get much smoke!

 

[mattyfab]

I gave the car some pasty on the bypass yesterday, and OMG, the smoke is unreal.
Mind you, the 330d BMW I was racing was doing it just as bad, so im sure im fine

 

[Randomman]

Yeah they are only tested on smoke, it can still fail without a particle filter though or a bad engine, or a bad MAP. A lot of people still refer to cats and decats on diesels though. Just wondering who's running a straight pipe where theres meant to be a filter?

 

[AwesomeSarah]

Mmmm
Yes the diesels dont have immisions to worry about , it is just a smoke test
I would say it would be great mod and NOT THAT expensive
Sarah

 

[davels]

hmmmm i'd keep the CAT and just remove the rear silencer, removing the CAT can reduce back pressure the DERV uses to get the turbo spooling quicker, i had the back box removed on mine with a map and had no troubles without smoke or too much noise, which is another prob with the full decat.

 

[Ibiza 130 tdi]

hmmmm i'd keep the CAT and just remove the rear silencer, removing the CAT can reduce back pressure the DERV uses to get the turbo spooling quicker, i had the back box removed on mine with a map and had no troubles without smoke or too much noise, which is another prob with the full decat.

It does smoke a lot more with the full decat. I'd agree with Davels. Try taking all the silencers off and leaving the cat on. If you still want more noise, take it off.

 

[Rosco906]

when my centre sections goes im gona have a stainless steel pipe made up from cat back no box's to the fr backbox

 

[muddyboots]

Even if your TDI smokes under full load, remember the MOT smoke test is done with no load, so it would have to be seriously unwell to fail...

 

[Ibiza 130 tdi]

when my centre sections goes im gona have a stainless steel pipe made up from cat back no box's to the fr backbox

There is no centre box on a diesel...so having the cat and fr back box would be no different from standard spec...

Correct me if i have misunderstood. i normally do.

 

[Rosco906]

pretty sure ther'e's a middle box after the cat on mines.

Mines is the 100 pd tho

 

[Ibiza 130 tdi]

pretty sure ther'e's a middle box after the cat on mines.

Mines is the 100 pd tho

I don't know....I thought they all had just the cat and the backbox....

Like i said, I'm normally wrong so...

You're probably right bud.

Lob off the two silencers then and leave the cat, see what it sounds and goes like.

 

[Rosco906]

also mines is an 02 reg

Anyway its not important the now. Will wait till its fooked then just leave cat on for back pressure

 

[Bunnin]

Lil off subject but ave a look at my new Milltek ! brand new design, oh n some pics if u havent had a butchers on the 1 page
Cheers Bunnin
http://www.seatcupra.net/forums/showthread.php?t=118047&page=2