OK, as far as im aware, a decat is just a bit of pipe, with no cat in it? correct? so could i not just take my cat off and weld a bit of pipe in?

Thanks

matt

I've never understood people who pay money for a de-cat from milltek etc. It is exactly the same to simply cut the cat out and weld in a length of standard exhaust piping,which can be bought for next to nothing!And any mechanic will do it for about £20 or £30...

No need for pics mate,its an extremely simple job.

yeah? Im not doing it myself, got a mate who welds. But a decat is £100+ if its fairly simple then might as well do it

If your mate has a grinder and can weld your sorted,cut about 30-50mm from the cat on either side of it,then weld a length in,making sure to seal all the way around,and give it a spray with a bit of paint to reduce rusting.Its the really large section of exhaust in the middle of the system.

It loosens up a mapped vrs really well,and shouldnt cost you much more than a tenner if your mate does it for free.

People use the Milltek ones etc as they are a larger diameter pipe, therefore allowing more gas flow. This is especially usefuli if you are running a hybrid turbo

Alex

Yeah Alex i should have been more specific, replacing it with just a length of pipe is only worthwile if you have a standard system.Cheap and easy mod though.

A milltek cat back on its own,however,is a colossal waste of money.

Make it stainless to prevent rusting . . Not sure if it passes an MOT without a cat i heard some people talking about it but not sure.

Make it stainless to prevent rusting . . Not sure if it passes an MOT without a cat i heard some people talking about it but not sure.

No cat required for MOT, they just check smoke opacity.

Ahhh, alex`s point is quite importent since im trying to catch up my fellow fabia owners in mk lol. Hoping to have a hybrid in it by new year so thats that idea out the window. lol

thnaks anyway!

I found this

There seems to be a lot of confusion surrounding what a 'Cat' does, what happens when you remove it and the MOT requirements.

Here are the answers:-

The catalytic converter (CAT) helps to convert carbon monoxide into carbon dioxide. It converts the hydrocarbons into carbon dioxide and water. It also converts harmful nitrogen oxides back into nitrogen and oxygen.

The lambda or O2 sensor, is the key sensor in the engine fuel control feedback loop. The ECU uses the O2 sensor's input to control the amount of O2 in the exhaust gases and balance the fuel mixture, keeping it within a very narrow Air/Fuel ratio band of +/- 0.03% of 1.0 λ

The O2 sensor is fitted in the exhaust before the CAT, so removing the CAT will have no effect on the function of the O2 sensor, fuel mixture or the running of the engine other than to let it breathe better.

The current MOT test does not include a gas analyser check and as far as we are aware it will not be introduced in the near future, so you are quite within the law to remove the CAT in the UK.

I'm going to get a de cat with a bigger bore then get a full turbo back system at a later date

http://briskoda.net/fabia-i/de-cat-questions/125180/

Here's some pics of a decat for the fabia.