DPF delete? The government wants unlimited fines: what the proposal actually says

What is being proposed?

The Department for Transport ran a consultation, "In-use emissions of road vehicles: regulating environmental impacts", from 6 July to 6 September 2026. It has not yet published its response.

The proposal is that road vehicles in Great Britain, from 1 January 2001, must have their emissions control systems maintained so that the limits set when they were built still apply. It would be an offence to:

• use a vehicle that no longer meets its approved emissions standard because of how it has been maintained or modified,
• allow someone else to use such a vehicle, or
• modify a vehicle, or allow it to be modified, so that it breaks that standard.

The government says it does not plan to treat deliberate and accidental changes differently, or hardware and software changes differently. Poor maintenance would count as well as modification.

Which modifications would always be illegal?

The consultation lists four practices it considers always unlawful because of their proven effect on emissions:

• Removing a diesel or petrol particulate filter (DPF or GPF).
• Removing a three-way catalytic converter.
• Disabling the SCR or AdBlue system, often sold as "AdBlue delete".
• Tampering with the EGR system, physically or with an ECU remap.

Replacement parts do not have to come from the car maker, as long as they are legally approved. It is already an offence to fit or supply unsuitable parts.

Why the change?

The current rule only covers vehicles up to Euro 4 cars and Euro V lorries. In the consultation's words, "There is no requirement to maintain the functioning of the ECS of Euro 5 or 6 light-duty vehicles". That gap covers most diesel cars on the road today.

DVSA's market surveillance unit received 331 intelligence reports about emissions modifications in 2024, and the government believes this is only a small share of what goes on. DVSA would enforce the new rules, with a focus on the businesses that carry out illegal modifications.

How does this link to the MOT?

A missing or tampered DPF is already an MOT failure. Under the MOT inspection manual, these are all major defects:

• emissions control equipment fitted by the manufacturer that is missing, obviously modified or obviously defective,
• evidence that the DPF has been tampered with, such as a filter cut open and welded back,
• visible smoke of any colour from the exhaust of a car fitted with a DPF.

The proposal would add the risk of a court fine on top of the MOT failure. See our guides to MOT checks and MOT advisories.

What it means for drivers now

• No new fine applies today. Nothing changes until the government responds, lays legislation and the lead-in period ends.
• Buying a used diesel? Be wary of adverts mentioning "DPF delete", "EGR off" or "AdBlue removed". Check the free MOT history for emissions failures, and work through our used car checklist.
• Got a DPF problem? A repair, a professional clean or an approved replacement keeps your car legal. Removal does not.
• Replacement parts are not all equal: read how some replacement catalytic converters and DPFs failed DVSA tests.

New cars face tougher emissions rules too: read about Euro 7 from November 2027.

Questions drivers ask

Sources

• GOV.UK: In-use emissions of road vehicles: regulating environmental impacts (consultation, July 2026)
• GOV.UK: MOT inspection manual, section 8: Nuisance (emissions)
• Fleet World: Government launches consultation to plug loophole on in-use vehicle emissions

Facts checked against the sources above on 27 October 2026. Spotted something out of date? Tell us.