Be wary of the killer modifications

Posted on May 19th, 2017 by Rob Marshall


A recent inquest that concluded the accidental deaths of a young couple has highlighted the dangers of adapting (or deactivating) car anti-pollution systems, in a bid to either increase vehicle performance, or reduce repair costs.

Last December, the bodies of Tom Putt (20) and Nikki Willis (23) were found inside a Ford Fiesta ST that Putt, an apprentice at Ford Motor Company, had modified. One alteration was the removal of the catalytic converter. The result was that untreated carbon monoxide entered the interior as the couple were chatting, with the car stationary and the engine idling.

At the inquest, Detective Inspector, Rob Kirby, commented that there are inherent dangers in modifying vehicles and that:

“When modified, vehicles can produce significant quantities of carbon monoxide. This car was found to emit carbon monoxide levels 1,000 times higher than a factory standard identical vehicle.”

Kirby also advised owners of modified vehicles to satisfy themselves that such modifications are legal and safe but I argue that this is not always straightforward.

Illegal modifications: the social problem

While this example of illegal modification ended in tragedy, a significant number of companies in the UK offer illegal modifications that are very likely to increase the pollution levels emitted by the adapted vehicle.

It has become such common practice to make illegal modifications to engines and their anti-pollution systems, such as fitting a louder exhausts, cutting-out Diesel Particulate Filter cores, removing Exhaust Gas Recirculation valves (one of which is pictured) and even modifying engine ECUs (such as fitting tuning boxes), that it is perceived that they are acceptable.

One common argument is that, provided that the vehicle passes the MoT Test with the modifications installed, then they are sanctioned as being both safe and legal. This is incorrect. Type Approval determines roadworthiness in the UK, meaning that it is possible to have a modified car passing the MoT and be still unroadworthy. We have even come across insurance brokers sanctioning illegal modifications, making it even harder to identify alterations that are acceptable by law.

The legal situation

Several pieces of British and European Legislation exist in this regard but I shall cite the two UK pieces that I think are most relevant, although there are more. The Road Vehicles (Construction and Use) Regulations (Regulation 61a) cite that it is an offence to use 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 and this relates to the Type Approval standards (Euro III, IV, V, VI etc) and not the very basic MoT emissions tests. Section 42 of the Road Traffic Act reinforces that but adds that the person, who causes, or permits, the vehicle to be used, is also guilty.

Yet, there appears to be little appetite to enforce the regulations and stop the illegal tampering of emissions control equipment that are designed to minimise, as much as possible, the motor car’s effect on air pollution. Until action is taken on the many garages that are performing the work, illegally modified cars will represent a wider social cost that we all must bear.