Cat Bypass on LPG

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Mon 2 Sep 2002 15:06
Cat Bypass on LPG - MikeBlakesley
I have a Peugeot 406 with a knackered cat and I have been thinking about puting a cat bypass instead of replacing the cat. The car runs on LPG so has lower emmissions. Would it still pass it's MOT without the cat because of the LPG? Any advice gratefully received!
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Mon 2 Sep 2002 16:58
Cat Bypass on LPG - RichardW
LPG does NOT lower the emission that the cat reduces - CO, so the car will likely fail the MOT on CO. IIRC if the car was first used after about August 93, then it MUST have a cat fitted and should fail the MOT without. If you know the cat is kanckered then presumably it has already failed an emissions test?

Of course you could take the cat out, break the honeycomb out and refit it, and see if it will pass the emissions test - but that **might** be illegal, and I couldn't possibly advocate it.....

Richard
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Mon 2 Sep 2002 17:14
Cat Bypass on LPG - John S
Mike

I believe Richard is right. The tester will expect to see a cat, and I don't believe LPG will reduce emissions anything like enough to pass an MOT without one, especially NOx and CO.

Regards

John S
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Mon 2 Sep 2002 21:11
Cat Bypass on LPG - MikeBlakesley
Thanks for the advice.

Richard, the car failed its emissions last year on petrol but passed on gas ????? Don't ask me how!!

I'm still a little confused but I think that I'll probably end up having to get another cat. I'll try and get it through another MOT before I buy a new one though just out of curiousity.

Cheers
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Sat 14 Sep 2002 22:29
Cat Bypass on LPG - xz3
Hi

I have a mondeo on lpg, and have removed the cat and replaced with a "empty one", got through an mot ok.

anthony
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Mon 23 Sep 2002 22:39
Cat Bypass on LPG - Richard Turpin
Altering the mixture to make it very lean will help get through the MOT. Then make it normal again afterwards.
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