Decat or not Decat - that is the question!

[cdwood2010]

Theres a lot of discussion about the new MOT rules, and the fact that some of the older Mk2 V6 cars will require a CAT fitted, and although not tested for emmisions as a CAT vehicle, it has to be physically present. Or somthing like that.

Anyway, i spotted this on eBay and managed to bag it for £5:-



The main reason i bought it is that it is actually an MR2 CAT as far as i know, but on the inside:-



It's been stripped! I might even sleeve it properly, as it does expand into a a big tin box effectively, and that might feck with the gas flow a bit.

Figured that it might be worth a try, just in case the 'where the hell is your CAT young sir' question pops up.

Chris.

[mrT]

Well u got lucky there sir.. since cats have precious metals inside they seem to be the new stolen thing round here..
Someone I know had his work yard broken into overnight and they've cut a stole the cats from all his vans..
Having said so.. I have 2 perfectly good cats sat here that I am happy to sell if anyone wants them .. my car has no cat and that's how its staying.

A mate was following me few days ago when I decided to have a heavy right foot moment,
Mate says the car pops flames.. I can here it popping and banging it didnt expect flames like he described..

[Lee]

Just for reference Chris, what's the distance between the 2 mating faces of the flanges?

[cdwood2010]

Lee!

Hope you are well!

Can you send me a link to your 2GR build thread ( TB one if there is one?) I was trying to explain to Pat what a 2GR looks like in a Mk2 bay!

Anyway, the measurements on the cat free cat:-

Length - 420mm
Bolt holes - 110mm
Pipe diameter - 65mm

Some pics:-

[Lee]

I'm good ta, here's a link to all 32 pages of it http://www.twobrutal.co.uk/forum/sho...V6-Swap-Thread

Thanks for the dimensions, shall compare with what space has been left in my existing system when I get home, hopefully it may fit!

[cdwood2010]

Hi,

Sooper - will have a dig through it now!

Also it looks like youve got the same sized section in there, so hopefully a cat (or de-cat cat!) will fit in there nicely if you need!

[myers]

Yes guys Chris is correct, I just got the update at work and from april its a testable part.

7.1 Exhaust System 7.1 - page 1
The M.O.T. Inspection Manual Issue Date 01 January 2012
Information Method of Inspection Reason for Rejection
The overall security of the exhaust system
should be assessed; one or more exhaust
mountings missing may not be a Reason for
Rejection.
A durable repair to an exhaust system which
effectively prevents leaks is acceptable providing
the system is structurally sound.
A minor exhaust leak from, for example, a
connection joint or a pin hole, is not a Reason for
Rejection.
1. Check the security of the exhaust system.
2. With the engine running, check the exhaust
system for leaks.
3. On vehicles that qualify for a full cat emissions
test, check the presence of the catalytic
converter.
4. During all parts of the emissions test relevant
for the vehicle, assess subjectively the
effectiveness of the silencer in reducing exhaust
noise.
Note: For vehicles not subject to an emissions
test, the engine should be revved to around
2500rpm or approximately half maximum
engine speed if this is lower.
5. On Class 5 vehicles only, check that the
exhaust tailpipe is positioned so it is unlikely
that fumes will enter the driver’s or passenger
area.
1. An exhaust system not adequately supported.
2. A major leak of exhaust gases from any part of
the system.
3. A catalytic converter missing where one was
fitted as standard
4. A silencer in such condition, or of such a type,
that the noise emitted from the vehicle is clearly
unreasonably above the level expected from a
similar vehicle with a standard silencer in
average condition.
5. An exhaust tailpipe positioned so that fumes
are likely to enter the driver’s or passenger
area.

[cdwood2010]

Thanks for that.

Any idea what the cut off point is for a cat being present vs the car being cat tested?

Because a cat test will not end well (with an empty cat) but it sure as hell looks the part!

I've also got a full MR2 cat if anyone wants to borrow it!

Chris.

[Limeymk1]

Date wise I think it's the same as before with cats required if the car's been registered after Aug 1992.

An engine that's running sweetly is quite capable of passing a cat test without a cat being present. My old 4AGE used to get results that would pass a cat test.

[geoff]

Any one know what the noise limit is for the mot, Sorry Chris for hijacking

G