38 replies to this topic

[bobsy]

So can anyone tell me how easy is it for an amateur home mechanic to install a de-cat pipe/remove it for MOT please?

What tools/materials required?

Thanks,

Bobby

[Gone2]

4 or 5 bolts depending on ur cat. nowt to it once u eventually get the bolts loosened to start with.

[bobsy]

I will have to have a look at the weekend...never done any work on an exhaust before, would a de-cat pipe need some sort of sealant/gasket where it joins the system? or does it literally just bolt-on?

cheers,

bobby

[thegfb]

It wouldn't hurt to get a new gasket for each end from Ford before you fit it, probably just a couple of quid.

[MARTINR]

I needed a a deep 15mm socket, as the 2 rear bolts from the cat to the centre box have long studs.

If you need one I suggest a 6 point socket not 16, as the 16 point socket I tried first kept slipping off causing damage to the nut.

My socket was £5.99 from Halfrauds.

[bowlesy25]

using halfrauds sockets wont help regardless of how many sides there is to them :naughty: !

[dcag37]

my dad a few years back had his cat removed of his scorpio and his car passes mots so i guess if your emissions remain within the limits its okay

[thegfb]

Just a heads up, MOT rules changed this year and the cat now needs to be present to pass the test if there was one fitted from the factory.

[Bin_Man]

As stated above, the *presence* of a cat is now tested as well as the emissions level. A cat MUST be fitted if the car had one originally. I can't remember when they became mandatory in the UK - late 80's?? - but it will mean all but classics will need them.

Linky for info : http://www.motuk.co.uk/manual_710.htm

I have edited the thread title and the first post to avoid confusion.

[Mondeo_st_-freshling]

This also applys to the precats on the manifolds in the mk2's, I wanted to get new ones with the y pipe, now trying to source just a y pipe :S

[Bin_Man]

The "test" for cats is only visual. If the casing is there, the tester has no reason for rejection. So if you really want to decat, you can smash the internals out and leave the casing - that might be an option for you, but remember it will still need to meet the emissions criteria!

[Gary Price]

As well as my Mondeo TDCI I also have a Landrover discovery petrol.
The insides of the cat broke up and started rattling. I removed what was left to get rid of the noise.
It has an LPG conversion so no problem with emissions at MOT time (last test was 0.03%). Hence it actually passes for a CAT Petrol car but for some strange reason because it is LPG it is allowed 3.5% CO.
It it was tested while running on petrol it would fail (its about 1.2%).
If it wasn't LPG converted it would need a new CAT to pass.

[thegfb]

Mondeo_st_-freshling, on 22 February 2012 - 09:37 PM, said:

This also applys to the precats on the manifolds in the mk2's, I wanted to get new ones with the y pipe, now trying to source just a y pipe :S

How do you know that?

AFAIK, precats are not considered catalytic convertors for the purposes of the MOT test.

[stevegtuk]

Bin_Man, on 22 February 2012 - 07:48 PM, said:

As stated above, the *presence* of a cat is now tested as well as the emissions level. A cat MUST be fitted if the car had one originally. I can't remember when they became mandatory in the UK - late 80's?? - but it will mean all but classics will need them.

Linky for info : http://www.motuk.co.uk/manual_710.htm

I have edited the thread title and the first post to avoid confusion.

Hang on. Looking at that link.
No.3On vehicles that qualify for a full cat emissions test, check the presence of the catalytic converter.

Enphasis on the "qualify for full cat emissions test. That mean diesels that dont qualify for a full emissions check wont need to be checked if they have a cat.
So its only petrol models that have emission test that need to have a cat.

[frembrit]

Has anyone had their car fail for not having a CAT? Mine just passed without the main CAT, passed emissions ok too (though they shouldn't have tested it as the car is on LPG, unless the MOT has been changed for that too)

[stevegtuk]

For those that are unsure diesels dont have to have a cat. just read the last point on this from Vosa themselves.

http://www.dft.gov.u...Notice 3-12.pdf

[thegfb]

frembrit, on 03 May 2012 - 06:17 PM, said:

Has anyone had their car fail for not having a CAT? Mine just passed without the main CAT, passed emissions ok too (though they shouldn't have tested it as the car is on LPG, unless the MOT has been changed for that too)

Apparently for January-March, if the car would fail on the proposed changed for this year they still passed it but put it down as an advisory.

I also read somewhere else recently that the 2012 changes still hadn't been properly implemented and fails were still being recorded as advisories.

[nilagin]

thegfb, on 04 May 2012 - 06:11 PM, said:

Apparently for January-March, if the car would fail on the proposed changed for this year they still passed it but put it down as an advisory.

I also read somewhere else recently that the 2012 changes still hadn't been properly implemented and fails were still being recorded as advisories.

The advisory period on these new changes has been extended to run into the Summer.

[Gary Price]

frembrit, on 03 May 2012 - 06:17 PM, said:

Has anyone had their car fail for not having a CAT? Mine just passed without the main CAT, passed emissions ok too (though they shouldn't have tested it as the car is on LPG, unless the MOT has been changed for that too)

My Landrover is on LPG, when I take it for MOT, I make a point of telling them it is LPG. It still gets emmision tested but the limit is 3.5% instead of 0.5%. I'm not sure if they still check for presence of the CAT though. Mine looks like it has a cat fitted (external casing in tact ) but the insides exited several years ago. I don't know why we are allowed a higher level on LPG, mine can easily pass at 0.5%.

Gary