Diesel Particulate Filters.
 

It would appear that many UK motorists are driving about without Diesel Particulate Filters. The current MOT doesn't always pick up if it has been removed, and though illegal to drive a car without one it is not illegal for a garage to remove it. A change to the MOT will improve the situation, but there are also calls for spot checks to be carried out on diesel vehicles (as there currently are for checks on the fuel being used).
'Thousands' driving without crucial diesel filters - BBC News

Yes a friend of mine in the Motor tuning business removes them for customers if they request it. The MOT check is just a visual inspection, and it's hard to detect a removed filter when it's encased in metal. Bit of a backwards step, it's a shame as the cars run better, perform better and get better economy without the DPF'S. Now GPF'S are required for petrol cars, the problem is going to get worse.

But surely they pollute more? The whole point of the filters is to reduce the amount of particulate materials diesels put into the atmosphere, or does that not trouble you?

From what I can find on Gasoline Particulate Filters I can see little downside. Costing £25, no maintenance required and no effect on fuel consumption.
https://www.greencarguide.co.uk/feat...te-filter-gpf/

Yes, the particulate emissions increase obviously, but as the article points out, replacement is expensive, especially if you have an older vehicle. Pollution never has or will bother me as I live very rural with very few people or cars, but if I lived in or near a city, it would certainly concern me.

Can't see them being that much cheaper, they have the same job as the DPF'S and they are quite expensive. If you test a brand new petrol car V's a brand new diesel car, you'll find the particulate emissions are far worse on the petrol car, hence the need to start enforcing GPF'S.

Go to YouTube and search for rolling coal. Additionally, the current administration has cancelled the entire budget for climate change research and made it illegal for scientists on the government payroll to speak on the matter or even use the phrase "climate change"; they're dismantling the EPA (Environmental Protection Agency), and are loosening or eliminating pollution laws. There's a special kind of stupid happening there, both in the population and in government.

For the record, my Audi Q5 has a 3.0 L diesel engine (the special Dieselgate Edition). As much as I like good fuel economy, I also like that my vehicle does not belch black smoke (thanks to the Diesel Particulate Filter) and the exhaust doesn't stink (thanks to the Diesel Exhaust Fluid).

Also for the record, I believe a person is hypocritical when they remove their DPF citing increased fuel economy while employing ordinary driving habits or worse (i.e., a not fuel conserving driving style). Well, it might be hypocrisy, or non-accountability, or just ignorance, or callous indifference to the welfare of others.