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The mkiv Supra Owners Club

De-catting and M.O.T.'s


AJI
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Hello people,

 

 I'm thinking of de-catting my T-T and was wondering whether it would pass an M.O.T. with the cats removed?  

 

 I think the legal standpoint is that if a vehicle had cats in the first place then to pass an M.O.T. it must always have them on. Is this right??

 

Part two of the this question is : Is there a noticable performance advantage with the cats removed?

 

Thanks for any help,

 

AJI

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I just got an MOT for mine. I put the cats back on especially, and then he didnt even do a gas test. So I then spent another two hours refitting the downpipe. I guess that it is the luck of the draw. Mine is a 93K so by rights it should have cats.

 

As to the performance difference - it is huge. My TT is quick with the cats on and mental without them. This is with a HKS Hiper. If you have a stock exhaust on it then decatting will not give such a dramatic increase. The stock system is very restrictive. The HKS is basically a very large pipe with no restrictions....

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Quote: from AJI on 12:52 pm on Oct. 8, 2001[br]Hello people,

 

 I'm thinking of de-catting my T-T and was wondering whether it would pass an M.O.T. with the cats removed?  

 

 I think the legal standpoint is that if a vehicle had cats in the first place then to pass an M.O.T. it must always have them on. Is this right??

 

Part two of the this question is : Is there a noticable performance advantage with the cats removed?

 

Thanks for any help,

 

AJI

 

It's my understanding that it's age related. If they'd fitted cats to a 1920 Studebaker, you could have it MOT'd without. All MKIV Supras have to have cats.

You could do what some do, put back cat no 2 before MOT and run it hot before going in for the MOT, then swap it back immediately after, or you could do what others do;

 

find a small MOT testing station with a sensible proprietor, explain that you *could* put the cat back on, drive in, get the MOT, drive back out and take it straight back off again, OR, he could just test the car against non-cat vehicles. At least one person I know does that but then you've got to find a sensible testing station.

 

Performance difference? Oh yes.

 

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I put mine through with no cats, and it passed emissions. As long as it did that, they couldn't care less whether the cats were fitted or not.

 

Can't comment on the performance difference cos I've never driven a stock TT. But mine without cats is damn rapid! :biggrin:

 

P.

 

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You can get through legally without cats on a 93-95 registered car. Best to make it J-spec if you want to be doubly sure!

 

BUT at the end of the day its down to the tester's discretion. If you know your tester and know what he'll do then make your mind up that way.

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