What Cat?

[DUB BOY]

Right guys, my cars been remapped stage 1 by AMD, hasnt got a Cat on it at the moment, i have just ordered a full jetex stainless system for it, but its cat back, i do need a CAT as i understand it is illegal, anyone know if it would be okay to put a standard one back on, or any other ideas. Such as sport CAT's. The thing is i cant afford to get any more points as i just received 3 for my old mk1 golf being too low, and if i get 3 more my license is gone i dont really want to spend too much on one.

Thank Sam

 

[DUB BOY]

anyone?

 

[willives]

Diesels don't need cats, theres no emissions test on the MOT, just a smoke test.

I have a straight through system with no problems.

 

[DUB BOY]

Diesels don't need cats, theres no emissions test on the MOT, just a smoke test.

I have a straight through system with no problems.

seriously mate? do you have any proof of this just so i can be on the safe side, if this is true thats great.

 

[devonmikeyboy]

Diesel cars don`t need a CAT mate. People have been removing CAT`s from diesel cars ever since companies started to fit them. Exhaust companies like Milltek etc make down pipes with the CAT removed.

 

[rallynut]

how much louder would a standard system be without a cat?
and what difference in performance?
am i right in saying there will be less smoke as all the soot wouldnt have anywhere to gather?

 

[DUB BOY]

sweet saves me a small fortune then

 

[MJ]

am i right in saying there will be less smoke as all the soot wouldnt have anywhere to gather?

No you'd be wrong pal, the cat reduces alot of the smoke you'd expect see coming out of the back of a diesel, i removed mine on my old leon and even with just the cat gone it smoked its nuts off.

 

[devonmikeyboy]

No you'd be wrong pal, the cat reduces alot of the smoke you'd expect see coming out of the back of a diesel, i removed mine on my old leon and even with just the cat gone it smoked its nuts off.

Very strange as a CAT isn`t designed to remove soot just change the toxic gasses through a chemical process that are being emitted by the engine.

 

[MJ]

Very strange as a CAT isn`t designed to remove soot just change the toxic gasses through a chemical process that are being emitted by the engine.

Yeah its designed to act as a 'catalyst' (something that speeds up a chemicle reaction) in order to remove certain harmful chemicles from the exhaust gases.

Strangley enough once mine was removed (the first mod i did) the amount of smoke increased dramaticly on hard boost (running standard ecu software with no electrical or mechanical faults).

 

[devonmikeyboy]

Not that i am saying your wrong or i disbelieve you but that has never happened to any of my or my friends cars that has been noticed.

 

[MJ]

to be honest i think it might have just been a (rather nasty) characteristic of that particular leon because once it was re-mapped it smoked like it was on fire! - heavy black soot (which was reduced by the cat) and i dare say it was down to incorrect fuelling, yet it was ok on fuel and never threw up a fault???

 

[S3 AKR]

Removed mine with the Milltek and its since gone through an MOT with no issues too. No extra smoke, some extra poke and a small drop of about 3-4 mpg so it only does about 44/45mpg at 90mph now!!

 

[conkerman]

Could not find a soitable DFT link but have a look at

http://www.haynes.co.uk/webapp/wcs/...TView?langid=-1&storeId=10001&catalogId=10001

Cat is not required for MOT, but is used to reach the reavent Euro emissions level for homologation purposes.

The cats used are generally basic oxycats used to reduce HC and CO emissions.

Conks

 

[Andrewcupra TDI]

mine felw through mot test , even threw a fault up on the mot computer as being too clean for a diesel car !!!

altho i now and then have clouds of smoke

as for noise not much difference to oem noise apart from full throttle is a little louder

under normal load its the same noise

cars a leon cupra 150 tdi with full milltek resonated system