MOT and de-cat's

[weagie]

Im looking into doing a full stainless system and wasnt going to bother having a cat fitted but will this be MOT okay? Im under the impression that its only cars made after 2001 that had to have them fitted for an MOT. Obviously I dont want to go to all the trouble of making a sysytem without a cat to find that I wont pass the test.
Also theres a 02 sensor before the cat, is this going to cause any hassles if there is no cat fitted?
What do you guys have fitted?
Cheers

[stephenevans99]

Any petrol car after 1992 iirc needed a cat.

[hemihusky]

my car has been de-catted but passed emissions fine n therefor they passed it. im not sure

[Tomcat]

Think it depends if you can find a sympathetic mot tester

[weagie]

Yeah true, gotta be worth it going without though

[p fandango]

BT used to pass with a decat

[jdavis]

I thought it came under the "it was manufactured after 1993 so has to be fitted with one" maybe use a hollowed out one?

[weagie]

Think I'll just go for it and lose the cat and see what happens. Has any one had issues with management lights coming on or poor running without it?

[craigoodwood]

my mot is tomorrow, i asked the tester last week whether it has to be seen to have one fitted or whether it just needs to pass emissions, he said it does need to be seen to have one fitted however if it was hollowed out they would not check it and also if there was a cover over where it should be they wouldnt be able to verifie it was fitted...

[MoleT-5R]

Mine has the cat knocked out of the standard pipe, as the cat collapsed blocking it.
Mot has always been ok,co2 emissions ok, but just a tad high on the hydrocarbons and no lambda light issues

[p fandango]

Has any one had issues with management lights coming on or poor running without it?

It'll only throw a cel light if you've got a second lambs sensor after the cat. Not sure which 850's had the 2

[Ettienne]

I think iirc its a fail if its not on, but mine went through with cat removed the cat housing still in the exhaust as emissions weren't high.

[jamesy12345]

I think iirc its a fail if its not on, but mine went through with cat removed the cat housing still in the exhaust as emissions weren't high.

My T-5R just failed due to being having no cat installed, didn't even get to emissions....they wouldn't even entertain the down pipe with cat I had in the boot due to missing oxy sensor connection - "would cause a check engine light"

[Ettienne]

Mine still looked like it was installed.

My other 850, friendly mot inspector had the emissions machine genuinely break the morning of my mot, he continued with mot and didn't do emissions as he didn't have to use faulty equipment or something, well he is my neighbour lol

[martin_r_smith]

Mine doesn't need one! But I do also have a sympathetic tester.... My brother lol

[oblark]

If a car was manufactured with a cat then it needs to have it fitted to pass an MOT, also if you can be fined by VOSA if the cat has been removed.

[p fandango]

i've got the best of both world. Ferrita race cat with silencer, or with the flick of a switch a decat with straight thru exhaust. & all mot happy

[Sweep]

Doesn't the above cause a restriction/obstruction in flow?

[Henk]

it just dumps the exhaust gas straight out of the bottom when the butterfly is open.
Or most of it anyway, being the path of least resistance. In fact the passing airflow probably helps.
Graemewelch is going to love those welds

[p fandango]

Doesn't the above cause a restriction/obstruction in flow?

it may have an adverse effect when the valve is closed, but i'm not really bothered what happens when its like that