DPF removal gutting MOT test fail pass diesel particulate filter

Figures from the DVSA have revealed that over four times the number of diesel cars have failed the MOT test since the introduction of new emissions testing rules.

Since 20 May 2018 the UK government has changed the MOT rules for diesel vehicles. These changes will result in a “major fault” if the MOT tester:

  • Can see smoke of any colour coming from the exhaust
  • Finds evidence that the diesel particulate filter (DPF) has been tampered with – this captures and stores exhaust soot to reduce emissions from diesel cars

More on the MOT changes in our previous articles – MOT DPF deisel changes

An MOT “major fault” calls for the vehicle to repaired immediately and can not be legally driven on the road until it has fully passed it’s MOT. Not having a valid MOT can result of a fine of up to £1000.

The figures speak for themselves

Fuel type20 May 2017 to 19 November 2017 20 May 2018 to 19 November 2018
Diesel58,004 238,971

As you can clearly see from the figures above, the new MOT rule has seen over a four fold rise in the number of vehicles failing the MOT test due to the new rules.

These figures not only reveal an increase of over 411% for diesel car MOT failures, they could uncover the sheer extent of emissions cheating by owners having their DPF filters illegally removed. Many may argue that they didn’t realise DPF removal would one day come back to bite them or that they had bought a car without realising that the DPF filter has been removed. Either way, it’s the owners responsibly to ensure the road worthiness of a car, during ownership and when looking to buy.

Yes, DPF filters are expensive. They do go wrong and in early Euro5 and even some Euro6 cars (looking at you Nissan / Renault) poor design compounded the issue. This isn’t an excuse or justification to removal a vital component that helps curtail the cancerous emissions being belched out of diesel cars.

Check before you buy

We recommend that anyone looking to buy a diesel powered car (yes, people are still buying them) should have the car inspected before handing over the cash. DPF filters can be extremely expensive, sometimes costing more than the vehicle itself.

MOT Failure rates

As for the MOT test as a whole, the figures since the MOT changes came into force remain steady with an eye opening failure rate of 33.2% for diesel vehicles and 34.7% for their petrol counterparts.

Our thoughts

We can’t say that we didn’t see this coming. DPF filter removal services littered owners club forums, facebook groups and even google adverts for years up to these changes to the MOT test. Unfortunately, for many owners may now face either a hefty bill for the refitting of a brand new DPF or the stark reality that their beloved cancer machine is no longer economical to repair. 

Either way. We all benefit.

Cleaner cars, cleaner air. 

Have your say

What do you think about the new MOT test? Was it all too little too late? Have you been faced with a bill for a new DPF after having it “deleted”. Did you buy a car unknowing that the DPF had been illegally removed? Let us know in the comments below.

Related Articles & Futher reading

.Gov website – MOT Inspection Manual (updated May 2018)

[amazon_link asins=’B00VVWW5S6,B06WWBJWSK,B013KIPT2C,B06WW5KKYV,B01MG1OEZ7,B01N5NNFTA,B01GYCO20Q,B014WMMNTW,B01081ZS1G’ template=’ProductCarousel’ store=’hypermiler-21′ marketplace=’UK’ link_id=’4d196b8f-bfca-11e7-ad2e-794b99a25756′]