I’ve been following this for a while. It’s all rather confusing. I’ve had to deal with and work within legislation for my working life. The MoT manual says clearly and unambiguously a ‘missing original catalyst’ is a failure. So the tester can fail a car on that and it’s on the car’s MoT record. The manual does not say ‘but if it passes the emission test it’s ok’. However, the reply from VOSA does seem to indicate ‘if it passes the emission test’ it’s ok. BBR have presumably read the rules and provide a compliant item for customers. They have not done that for no reason.
Likewise noise. The regulations state a replacement exhaust can’t be noisier than the original, but VOSA say if the tester thinks it’s not too noisy it’s fine.
It’s all down to the person carrying out the test. Clearly, modify your car at your own risk and deal with the consequences if it causes MoT problems. Your choice.
JS
Exactly, as I said at the very beginning.
Clearly I won’t be getting Christmas cards from everyone this year. 
It’s interesting that the reply from VOSA refers to the “Road Vehicles Construction and Use Regulations 1986”, but I believe that the MOT test is conducted in line with the Road Traffic Act.
I also believe that the MOT Testers Manual is written in the way that it is for a good reason, to quote the Man from VOSA…
“…not unreasonably above the noise level you’d expect from a similar vehicle with a standard silencer in average condition.”
Unreasonably above, similar vehicle, average condition. There could be a lot of opinion in an assessment of a vehicle based on that description I think. But take it word for word and someone could probably justify passing pretty much anything.
With regards the exhaust system the Testers Manual states “You only need to check components that are visible and identifiable, such as catalytic converters, oxygen sensors, and exhaust gas recirculation valves”
Visible and identifiable… so if you can’t see a component (if it’s been removed for example) is it testable?
Frankly until VOSA catch up with the likes of Germany TUV testing these problems will continue to invite debate. At some stage, if the Government of the day are serious about cutting vehicle emissions, particularly NOx, then there will have to be a root and branch change to vehicle emission testing. This could be with on line connection of the testing apparatus and the car to a central database containing all the car model details of it’s original homologation parameters against which it will be passed or failed, presumably with a tolerance for “in use” variation. As a result I suspect that they will at some stage have to take the pass/ fail decision out of the testers hands. Inevitably this will result in a significant increase in cost both for the testing facility and the vehicle user. There have already been noises from VOSA about the future of the MOT emission test, it’s just a matter of what and when rather than if…
What a waste of time even thinking about it. In 10 years you will struggle to buy a car with a combustion engine. That’s the governments answer.
The tester has to use their judgement on some items but it’s not completely arbitrary. He needs a reason to fail it. The rules once let me get a pass from a marginal emissions failure when I explained the rules regarding cat testing Eunos Roadsters (and the tester checked with VOSA that I wasn’t making it up).
To reduce overall emissions, its probably more effective to incentivise renewal of cars, getting the old ones off the road. From 2030 onwards, there will be a diminishing requirement for emissions testing at the MOT station, as more and more cars on the road are zero emission.
As we’ve drifted on to talking about electric cars I thought Harry Metcalfs views were interesting:
Hi everyone, well, I have just spent a great deal of time reading about mot failure and advice… Today I took my 1994,Eunos,1.8 Roadster for a mot, and it failed on c. O emissions, just done a full restoration on this car reusing, refirbing as many parts as possible, complete engine strip and rebuild, new everything, new s/s exhaust, new cat, new lambda, etc, problem as suggested by someone ie do a 5 mile drive, No, on sorn and illegal, I ran for 1 hour but still failed, mot man said it may not be hot enough, any advice??
I appreciate it’s SORN’d but as long as you pre book it you are allowed to drive to the centre/garage by law. Perhaps by Text or Email confirmation?
Get it nice and hot on route.
Just an opinion.
Sroll down to Table 1.
My first thought is whether it got tested as a cat-equipped car or not. As it’s a '94 Eunos Roadster it should get a non-cat test which is much more lax than the cat test.
Do you know which test it got and what were the actual emissions?
The non-cat test allows 3.5% CO and if it failed that then there is bound to be something wrong (typically either a non-functioning O2 sensor or coolant temp sensor).
There are currently around 32 million cars in use in the UK. Even replacing at 1 million electric cars per year will still leave 20 million in use by 2030. Presumably these will still need an MOT test?
Electric or not, cars will still need an MOT test. It’s a wide-ranging safety test and exhaust emissions are just one small part of it.
Yes but this thread is purely surrounding emissions.
I don’t know what the average age of a car in the UK is but it’s increased over the years. If the last petrol cars hit the road in 2030 then they’ll only start to get MOTs in 2033 and should be around for over a decade after that.
They’re not stopping making petrol cars in 2030!
There will be petrol engines around for decades. But demonising numbers. Petrol will become expensive and help price them off the roads. Thin end of the wedge and all that.
I believe '94 was the changeover year, possibly August being the month. I have a '94, it has a cat and needs to comply.
Surely with “supply and demand” fossil fuels will become cheaper as demand drops? It will be a very unpopular Government that artificially increases fuel costs through taxes, that will disproportionately affect poorer members of the car owning electorate unable to afford the extra cost of buying a new EV.