Decat and MOT

[Toms306]

Hi guys,

Thought you might be interested in this....I emailed vosa regarding the presence of a cat rule to ensure a decat will pass the MOT -

Hello there,

There seems to be very mixed opinions across the internet and forums
regarding the new 2012 rules for MOT testing. Now I am interested in the
'presence of a cat' rule.

The way I have understood it is that a catalytic converter MUST be present
on a vehicle which was factory fitted with one, but only if it requires an
emmisions test to pass the MOT. Now I know diesels DO NOT require an
emmisions test, just a smoke density test, so am I correct in thinking that
a diesel with a 'decat' (straight pipe in place of the original catalytic
converter) will pass the MOT like this, assuming the pipe is secure and not
leaking at all.

I ask becuase this is a very popular modification and myself and others
would be very grateful to know exactly whether this is reason for a refusal
or not.

Thank you for your time,

Tom

The answer I got was -

Dear Mr S,

Thank you for your email enquiry dated 12th April 2012, concerning an MOT.

The check for a CAT only applies to petrol engined vehicles which qualify
for a full CAT test. There will be an update to the IM in Spring which will
clarify this.

The fitment of a catalytic converter to petrol engine vehicles is mandatory
for vehicles of the specified age and type e.g. passenger car, goods etc.
The MOT Inspection Manual can therefore specify exactly what petrol engine
vehicles must have a catalyst fitted.

I hope this information has assisted you with your enquiry, but if you have
any further questions please do not hesitate to contact us again.

Kind Regards

Rebecca
Customer Service Centre
VOSA Operations Directorate

So we're definitely fine with de-cats on diesels......

Tom