The Department for Transport (DfT) has published new guidance covering the legal, safety and health implications when it comes to modifying vehicle emissions.

The guidance encourages vehicle owners to seek professional advice from mechanics to ensure that any vehicle modifications are safe and within the law.

The DfT said: “It is not always obvious to vehicle owners that some modifications will make the vehicle illegal to use on the road, irrespective of whether the insurer is prepared to provide cover.

Exceeding type approval limits

“For example, removing a catalytic converter or diesel particulate filter will almost certainly result in a vehicle’s emissions exceeding type approval limits and make the vehicle illegal to drive on the road.

“Engine re-mapping may also result in non-compliant emissions.

“It is the driver who is responsible for ensuring compliance.”

Regulations

Under the Road Vehicles (Construction and Use) Regulations (Regulations 61(7) and 61A(3)) and the Road Traffic Act 1998 (Section 42) it is an offence to use on a road a vehicle which has been modified in such a way that it no longer complies with the air pollutant emissions standards it was designed to meet.

The potential penalties are £1,000 for a car and £2,500 for a van, lorry or bus.

Under the Road Traffic Act 1988 (Section 75) it is an offence to alter a vehicle in such a way that the use of the vehicle on a road would be unlawful.

A person altering the vehicle may be found guilty of an offence under the Act and the potential penalties are unlimited fines.

“Potential to kill”

The DfT adds: “A badly modified vehicle has the potential to kill its occupants and pollute the air.

“Making changes to the engine management system in an attempt to increase performance, coupled with the removal of all or part of the emissions control system, may lead to significantly higher levels of harmful exhaust emissions which can then find their way into the vehicle’s interior.

“Incorrectly fitted parts or unapproved changes to a vehicle can lead to a potentially deadly outcome for vehicle occupants.”

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