Part 2 - New MOT rules for diesels: catalytic converter implications

[Shaun]

VOSA have been most helpful in answering my emails, so I've asked them why their information hasn't been been more forthcoming to MOT testers and owners who will be affected. I've pointed out that the wording in their test manual gets the right result if it's followed closely, but wouldn't it have been so much easier to clearly state that diesel vehicles are not subject to the full CAT test, so there can't be a refusal for a missing CAT where one was fitted from new?

 

The fact is that testers and owners on web forums are arguing as to whether fuel type makes a difference when it comes to de-catted diesels. Straight pipes tend to replace CATs mainly for performance-enhancing reasons, but motorhome and panel van owners with stolen CATs, are caught up in the same way if test rules apply regardless of fuel type. The relevant EU directive, which the new test rules are based on from January 2012, clearly makes no differentiation, so I asked how their test manual can suggest otherwise.

 

This is VOSA's reply:

 

**********************************************************************

 

Dear Shaun,

 

Thank you for your e-mail reply dated 19th December 2011, concerning new MOT test rules.

 

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.

 

However, whilst diesel engine vehicles are required to meet certain emissions limits for Type Approval, the method used to achieve this is not specified. It was left to the engine manufacturer to decide how to meet Euro 3, 4, 5 etc emissions standards.

 

For this reason, testers would be unable to readily determine which vehicles are OE fitted with a Diesel Oxidation Catalyst (DOC), Diesel Particulate Filter (DPF) or Selective Catalytic Reduction (SCR) system.

 

It was therefore considered that the introduction of a Reason for Rejection for a missing diesel catalyst at this stage, whilst complying with the Directive, was likely to lead to many incorrect failures, which is clearly unacceptable.

 

The matter is under review and may therefore change in the future.

 

****************************************************************************

 

I don't think the situation could be made any clearer than that, and there seems to be no way a diesel vehicle can fail its MOT purely due to a missing CAT. I thanked VOSA, and asked them if it might be worth making these facts much more widely known, to alleviate all the confusion. I then said I was putting my lobbyist hat on to suggest that due to the volume of CAT thefts from panel van and motorhome owners (at hefty cost to replace), and given that the benefits of the original equipment are not proven to be strictly necessary, there must be merit in keeping the status quo of just a smoke test for diesel owners. (Yeah, whatever, mate...)

 

Shaun

[Corky 8]

Shaun,

Just to Say Thank you for the time and effort you have put into this  issue, while it may only effect a few just now,if the theft of Cat,s continue it may effect the Many, Pre informed has its merits,  Thank you.

[Guest pelmetman]

Have I read this right :-S...........................So if your cat is stolen and you replace it with a bit of pipe, your van will still pass its MOT 8-)..........................Kinda takes the p*ss out of the LEZ (lol)

 

I'm tempted to buy a new works van >:-)

[malc d]

pelmetman - 2011-12-20 8:40 PM

 

Have I read this right :-S...........................So if your cat is stolen and you replace it with a bit of pipe, your van will still pass its MOT 8-)..........................Kinda takes the p*ss out of the LEZ (lol)

 

I'm tempted to buy a new works van >:-)

 

 

 

No - I don't think you have read it right.

 

My understanding is that they say that vehicles will be assessed on their emissions, not on how those emissions are controlled by the manufacturer.

 

So, if you fit a bit of pipe and the emissions are o.k. it will pass, if the emissions are not o.k. - it won't.

 

 

p.s. Well done Shaun - thanks for a useful bit of info.

 

;-)

[Guest pelmetman]

Well if it's based on emissions ;-) ...............I'd like to know what they are? as I have heard that if you add 2 stroke to your fuel it reduces your admissions..................and I did try 2 stroke for a while in the works van and it certainly made a difference to my uuuuuuuuumph :D........So much so I had fears for points on my license 8-)

 

 

[flicka]

great information Shaun

 

BUT now how do we find out which manufacturer took which route to achieve the objective (?)

[Shaun]

I think this is as much as we can expect from VOSA, when it comes to clarification of the new rules from January 2012, in relation to whether or not MOT testers should check for CATs on diesels. This email is the response to my mentioning the confusion which the current wording from VOSA has created in its documentation.

 

Note the reference to 'spring' as to when MOT tests can be failed for one of the new reasons, as opposed to when the rules actually change (January):

 

******************************************************************

 

Dear Shaun,

 

Thank you for your e-mail reply dated 20th December 2011, concerning new MOT test rules.

 

VOSA have proposed an amendment to the Method of Inspection in the Inspection Manual, so that it will read "On petrol engine vehicles that qualify for a full cat emissions test, check the presence of the catalytic converter".

 

However, this amended wording will not find its way into the Manual until the new testable components become failable in the spring.

 

[Harvey]

Job well done Shaun! :-D Thanks.

 

Harvey

[ham]

I have been told by a local Mot tester that any Vehicle under the new Regulations that has had its engine remapped or modified after delivery from the factory will be classed as a Mot Failure. And they will be based on the emission test. I asked the question about remapping and the missing Cats. The reply was if they are evident and a Modification to the Factory Specification and altered the emissions there would be a failure .I know of one garage techy who had is car Mot done before it was due this month because it had a warning light on and they were have a problem resolving the problem

[Guest Tracker]

ham - 2012-01-02 11:31 AM

 

I have been told by a local Mot tester that any Vehicle under the new Regulations that has had its engine remapped or modified after delivery from the factory will be classed as a Mot Failure. And they will be based on the emission test. I asked the question about remapping and the missing Cats. The reply was if they are evident and a Modification to the Factory Specification and altered the emissions there would be a failure .

 

Is this written into the rules or is it just this one person's interpretation I wonder?

 

As long as the emissions are within tolerances how can they tell whether a remap has taken place or not, whereas a missing cat will be pretty obvious?

[Brian Kirby]

Ah, yes, but! :-) Shaun's very beneficial correspondence with VOSA seems to have extracted a clarification that the presence or otherwise of a cat is not an automatic fail for a diesel engine, only for a petrol engine if originally so equipped. The pass or fail criterion for a diesel being emissions only, whether or not a cat is present, or was originally fitted.

 

I think ham's may be a different point? However, I also rather suspect he was talking to the monkey, and not to the organ grinder. :-)

[colin]

As the saying goes "proof of the puddings in the eating" trouble is not every ones taste is the same, so I guess there may be several failures made by less well informed testers, pretty much like happens with suspension assistors. The comical thing is any tester failing a vehicle due to a missing cat might well be compling with the EU directive, but not our governments enactment of the directive.

[Brian Kirby]

Don't think so Colin. I had a look at the directive and, so far as I could see, it says exactly what VOSA is saying. If the appropriate level of emissions for a diesel engine of a given year can be achieved without a cat the vehicle passes, whether or not a cat was original equipment.

[Harvey]

Shaun posted this in the original thread:--

 

" Here's the link, followed by the VOSA reply:

 

http://www.dft.gov.uk/vosa/repository/MOT%20Inspection%20Manual.pdf "

====

 

The link does not work now. Did anyone download it? It is I think, 'Crown Copyright' so maybe it should not have been given. I just wanted to read it again. I wonder if MOT testers get sent new / updated manuals or if they have to buy them .............. my son is a licensed MOT tester, I'll ask him. He does not have his own MOT station, but uses someone elses to do his MOT's.

 

If it is not available to 'the public' I wonder how they are to know about new rules before presenting a vehicle for test. I noticed in a thread in 'another place' that there was a link to some of the new rules one of which was that speedometers must be fitted and working. I don't believe they were included in the test previously........

 

................ as it 'appens my son just 'phoned me so I asked some questions:--

 

1) I asked how and where he gets the MOT testers manual updates.

Answer:- They are now on the MOT computer and are available only to registered testers.

 

2) I mentioned the new rules for 2012 . He said that several sources ( forums / facebook members etc, ) are saying that the new rules do not come into effect until later in the year ( April-May? ) but he has not seen anything official to say that and as far as he was aware they were from 1st January!

 

3) I mentioned the controversy / confusion about checking visually for a CAT. He said it doesn't mention any difference between petrol and diesel vehicles and he understood it is for both!

 

I told him of Shaun's communications with VOSA and their clarification of this rule and he said "Oh!" and he is going to look again.

 

My comment: So that just shows that Shaun's efforts were well worth while and that there *will* be some confusion among MOT testers at least until the next update of the Testers Manual..

 

My son also added the comment though, that if a vehicle which had to have the CAT emmissions test did not have a CAT fitted, then it would fail the test anyway without having to visually inspect for a CAT .

 

4) I menioned about the rumours going about that having a 'chipped' engine would fail an MOT.

His answer: " I wouldn't know it was 'chipped' "

 

I hope that is of interest.

 

Harvey

[DJP]

ham - 2012-01-02 11:31 AM

 

I have been told by a local Mot tester that any Vehicle under the new Regulations that has had its engine remapped or modified after delivery from the factory will be classed as a Mot Failure. And they will be based on the emission test. I asked the question about remapping and the missing Cats. The reply was if they are evident and a Modification to the Factory Specification and altered the emissions there would be a failure .I know of one garage techy who had is car Mot done before it was due this month because it had a warning light on and they were have a problem resolving the problem

 

Totally false information regarding the remap quote. The MOT stations have no way of telling if a car/van has been remapped. If it has an additional box attached then only a visual check will show something has been changed. The vehicle will fail if the emissions are in excess of the required level. This could be due to any number of reasons not just a remap. The failure would be on emissions only NOT on the fact the vehicle has had a remap.

[Harvey]

This is a link to an MOT testers manual. I have known of this for some years but had forgotten about it: I also didn't realise that it got updated; It does now include updates for Jan 2012.

 

http://www.motuk.co.uk/manual_710.htm

 

Harvey

[Shaun]

The way VOSA goes about things when it comes to MOTs, can seem bizarre. I had all that shenanigans with the van's spring assisters, which were regularly being failed as they appeared to testers to be bump stops, so the gap between the axle was deemed to be insufficient. VOSA was well aware of the confusion these new suspension designs were creating among owners and testers, but didn't sufficiently clarify the situation so as to prevent more incorrect failures. In fact VOSA muddied the waters further by saying to my Fiat dealership that testers should pass these vehicles, but might wish to issue a warning.

 

This CAT malarkey is another example of owner and tester confusion, but perhaps this can be put down to the fact that VOSA knows it isn't complying at present with the latest EU directive, but might well have to in time.

 

VOSA made no attempt to me to suggest they had a different interpretation of the directive, but simply that it wasn't practical to instruct UK testers to comply with it, because it would be almost impossible - given the variety of emissions equipment originally fitted - to state with confidence that a particular unit was missing.

 

The irony is that VOSA doesn't want incorrect MOT failures due to testers incorrectly concluding what originally fitted equipment would have been, but instead, due to a poorly worded manual, incorrect failures are quite likely for diesels, when a tester sees a through pipe where a box used to be, and makes the wrong call.

 

What remains to be seen is how VOSA reacts to the inevitable appeals which will arise if testers aren't properly informed en masse that diesels currently don't count for missing CATs.

 

Shaun