In recent years, automotive enthusiasts have embraced the trend of installing pop and bang maps in their vehicles, creating an attention-grabbing (but often unpopular) spectacle on the streets of the UK. This modification has gained popularity among car enthusiasts, as it simulates the crackles heard in high-performance vehicles. However, the legality of these modifications has become a hot topic of discussion, with a recent high profile prosecution of a tuning garage for providing a pop and bang map and fitting a decat.
In this blog post, we will explore the ins and outs of pop and bang maps and whether they comply with the legal regulations in the UK.
Are pop and bang maps legal in the UK? What exactly are they?
Pop and bang maps, also known as exhaust overrun or crackle maps, are modifications made to a car's engine control unit (ECU) to produce popping and banging sounds during deceleration or during gear changes. By modifiying fueling and ignition timing tables in the mapping, it is possible to delay the combustion process so that it occurs in the exhaust system. When combustion occurs in each runner of the exhaust manifold, it generates the distinctive pops and bangs so desirable to many car owners. Usually, it would be required to fit a decat pipe to get the full auditory experience.
Are pop and bang maps legal in the UK? Potential legal implications
The legality of pop and bang maps in the UK is a widely argued topic. While these modifications may not directly affect a vehicle's performance or emissions, they will almost certainly fall foul of noise pollution regulations. The UK has strict laws governing vehicle noise levels, and modifications that significantly amplify exhaust sounds could lead to penalties and/or MOT failures. If you have removed your catalytic converter and fitted a decat to fully embrace the pop and bang experience, your vehicle would no longer be suitable for use on the public highway, as any factory fitted emissions system must stay in place at all times.
With a recent case in winter 2023 where VOSA prosecuted a tuning garage for fitting a decat and pop and bang map without informing the customer of the legality and roadworthiness, it is advisable to always consider pop and bangs maps to be only suitable for off-road use.
Are pop and bang maps legal in the UK? What are the potential consequences?
DVSA and VOSA agencies in the UK have become increasingly vigilant about vehicle modifications, that contribute to excessive noise and exhaust emissions. We expect to see the spotlight shined even more closely on this topic in 2024. As a result, drivers with pop and bang maps may find themselves facing on the spot fines, vehicle impoundment or MOT failure if they are deemed to be in breach of noise regulations. Such prosecution may also create difficulties acquiring car insurance, which is already causing great pain to car owners due to rising premiums.
Are pop and bang maps legal in the UK? When is it okay?
If your vehicle produces crackles on the factory ECU calibration, then this is fully legal in the UK. Hot hatches such as the Hyundai I30 N, Mini Cooper S and Ford Focus RS, all produce these distinctive noises when in Sport driving modes. And of course, many high performance models such as BMW M and Audi RS, as well as supercars and hyper cars will tend to crackle on overrun. Where you should be careful is in the use of track specific driving modes, as it could be argued that these were never intended for road use, and pops and bangs in track mode could get you into hot water.
Are pop and bang maps legal in the UK? Conclusion:
While pop and bang maps can enhance the driving experience for enthusiasts, it's crucial to be aware of the legal implications in the UK. As regulations tighten, staying informed about noise standards and seeking professional advice can help car owners navigate the fine line between personalizing their vehicles and complying with the law. Flaunting your pop and bang map in a residential area or at a static car meet, is very likely to draw the attention of the authorities!