Hi MX5ers
Currently running stock exhaust but an exhaust manifold upgrade is in the pipeline, a 4-1 with decat.
How does this stand with the new MOT rules?
I’m no expert, but looking at the tester’s manual for the 20 May 2018 onwards test, Section 8.2.1.1 it defines inspection of emission control equipment:
This inspection only applies to vehicles requiring a full catalyst emissions test (disregarding the Basic Emissions Test) and is restricted to components that are readily visible and identifiable, such as catalytic converters, oxygen sensors, exhaust gas recirculation valves etc.
It goes on to state: ‘(a) Emission control equipment fitted by the manufacturer: missing, obviously modified or obviously defective’ is a major defect and therefore a fail.
It therefore appears missing or modified original emissions control equipment is in itself a major defect. There seems to be no allowance for partial removal even if an emission test is passed unless it is buried somewhere else in the document.
On the face of it. the new test looks like bad news for modified cars. From your avatar, you have a mk3 and therefore requiring a full catalyst emissions test. I’d put the ‘upgrade’ on the back burner if I were you. I think there are going to be some ‘interesting’ MOT discussions after May.
The link is:
https://www.gov.uk/government/publications/mot-inspection-manual-for-class-3-4-5-and-7-vehicles
(to add some humour, my car passed its MOT today. Whilst waiting I was chatting to the guy on reception and casually mentioned the revised MOT test planned for May 2018. ‘Is there?’ he said).
JS
The rule for a missing catalyst exists currently IIRC, it’s really about the tester being familiar enough with the vehicle to notice it.
Thanks everyone for your replies.
So I guess that the more OEM the installation looks the less conspicuous it will be and less likely to attract the attention of the tester?
I will take on board the post above and wait until there have been a few reports after the new rules come in.
It’s going to depend on how much the tester knows about a particular car and how much access they have. I have a Skoda Octavia which has a pretty large plastic cover under the engine compartment so you can’t see much without removing it. My MOT place put an advisory on it every time along the lines of unable to test various parts due to lack of access.
Ian
Robbie is right - a look at the ‘old’ rules shows a missing catalyst always was a ‘reason for rejection’. This level of modification has never been a concern to me. My thoughts are that the revised rules with increased emphasis on emissions control equipment, such as DPFs, may make testers a little more conscientious in their examinations.
JS
Hopefully after the new MOT rules are introduced in May we’ll get reports of people’s de-catted MX5s passing with no problems.
Being optimistic I’ve just renewed the insurance with esure, who were coming in joint cheapest on a comparison website but more importantly when I ran it through with an exhaust upgrade and remap (10-25% power increase) their price was only about £80 dearer. Many of the other insurers dropped out at this point and my current insurer (quote me happy) will not cover mods.
So if all goes to plan lots of MX5ers currently running an exhaust manifold upgrade including decat will get MOT passes with no problems and I can then upgrade myself, and just amend the existing car pol accordingly.
That’s the plan!
Hi MX5ers
It’s been over a month now since the revised MOT rules came into place and I’m curious as to whether people with an exhaust manifold upgrade and decat have experienced problems with passing the MOT?
I’m looking at doing this as my next project on the car and would appreciate some reassurance.
Thanks
Any comments folks?
Anyone with an upgraded exhaust manifold and decat recently had an mot?
Any issues?
Thanks
If you can wait until the beginning of September I can let you know…
Haha please do, looking at doing it late September.
Ps lovely car
Morning
My BBR 200 mk3.5 passed its MOT under the new rules this morning
Tester only comment was “lovely car, you obviously love it”…
Dave
Given what a catalytic converter does, and its importance on the air we breathe, why would people want to remove it?Is it not a tad irresponsible?
I would no more remove the cat from my MX5 than I would remove the DPF from my diesel car.
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Mine just passed the mot we had to get it really hot for it to pass but once the cat was up to temp it flew through
I have removed the manifold cat and running a 100 mid cat
Hi Dave
Thanks for remembering to provide an update - good news!
Can’t wait to get my shiny il Motorsport 4-1 fitted!
My interpretation of the the pertinent recent MOT rule changes are to reflect original equipment fitted.
An MK3 MX5 whether it be MK3, MK3.5 or MK3.75 was originally fitted with two catalytic converters - a maniverter and and underfloor cat.
Prior to recent changes the removal on the maniverter and replacement with a performance manifold was not a problem as long as the emissions test satisfied. Car is supposed to have a cat and still has a cat and passes emissions even though one of the original cats removed.
MOT rules now expect vehicles to be presented with original equipment setup, so the MK3 in all versions should fail the new MOT if not presented with both maniverter and underfloor cat as well as passing emissions. This relies on the tester knowing the original specification of the vehicle or being mandated to properly check.
I sincerely hope that strict adherence to the new MOT rules does not spoil the possibility of what appears to be a good mod on this car.
Mazda in York had mine for it’s MoT and service on Monday, a straight pass but I may need to rotate the tires as my rears are down to 3mm whilst the fronts are 5mm.
BBR manifold not an issue
Mine passed no problem a couple of weeks ago; BBR Super 200.