LPG Discussion Forum

So now I have LPG do I need the cat?

Martyn

you don't necessarily need the cat. As LPG is tested to a different set of values for emissions, it should pass without the CAT.
However if when you present the vehicle for MOT you fail to tell them it is on LPG there is a fair chance it will fail on emissions.

Can't see why you would want to remove the CAT anyway, you won't notice any difference in performance as the cats these days have a good flow efficiency, unlike earlier cats.

MoT rules are changing in Jan 2012. One of the draft amendments is about failing cars if a cat is absent, when one was originally fitted.
http://www.dft.gov.uk/vosa/publications ... papers.htm

ive scanned about for none cat fitted !! very grey area and nobody really gives you the answer you want (its ok)

my Civic type r Cat has a massive hole and is due for replacement, i was looking for the answer also its flies past the emmisions last MOT, new cat cost (no idea as yet) decat pipe is £120 in stainless

unsure what to do car runs on LPG all the time

Ricey155 wrote:ive scanned about for none cat fitted !! very grey area and nobody really gives you the answer you want (its ok)

Doesn't seem very grey to me.

Section 7.1, new Reason for Rejection 1c: c. a catalytic converter missing where one was fitted as standard.

This was taken from the proposed changes that were on the link that Ross posted above which have now been agreed as nobody objected. The only thing I can't find is when it comes into force (if it hasn't already).

I believe they are due to come into force in January 2012, but haven't seen that from a definitive source.

ive been in the same boat and visited my local MOT guy to ask him, his words and probably not up to scratch

if it passes the emmisions then it passes car or not cat, if it doesn't new cat required or retune if running badly

i was going decat but having tested my CAT its fine so stick with it

A pre July 1992 car is tested on the old carburettor emissions limits, even if it happens to have a cat fitted, as some were. Does this new rule mean that a cat would have to be present, even though it would not need to be working for the car to pass the relevant emissions standard?

Precisely.

tommo2009 wrote:However if when you present the vehicle for MOT you fail to tell them it is on LPG there is a fair chance it will fail on emissions.

How so? All my LPG cars have run cleaner on LPG than they do on petrol, even my Range Rover on a single point system

If it is correctly set up it will pass, especially with the correct test (Basic Emissions Test)