DPF and catalytic converter: how to prevent problems through preventive maintenance

Our cars are polluting less and less, and that's good for the planet. But there's a slightly less pleasant side to the coin: it increases the risk of breakdowns.

Yes, modern cars are fitted with equipment to reduce pollution. Diesel particulate filters recover pollutants and then burn them off. Catalytic converters use chemical transformations to neutralise the most harmful pollutants into carbon dioxide. To avoid breakdowns, there are simple ways of ensuring that your car remains in good working order over the long term.

A general rule: drive !

To avoid problems with your car's DPF and clogged catalytic converter, it's vital to drive regularly. The diesel particulate filter needs to be regenerated regularly to eliminate polluting particles and avoid clogging. Without this, the particles will clump together until they are completely clogged. If this happens, your engine will gradually choke and kill your catalytic converter in the process!

To understand the importance of driving regularly and over sufficiently long distances, you need to understand how a diesel particulate filter works. To carry out a regeneration cycle (which will destroy the particles), a certain temperature must be reached in the exhaust line. Most of this heat comes from the engine. To provide it optimally, you need to make a sufficiently long road journey, of around 30 minutes, at least once a month... And drive at a certain engine speed!

Active regeneration can also be carried out in a car centre, but this can add extra costs. Peugeot, Citroën and DS Automobiles HDI diesel engines use cerine, an additive that reduces the temperature at which particles are burnt by a good hundred degrees. However, it's important to remember that these anti-pollution devices mean that you have to drive long enough... That's why it's highly inadvisable for city-dwellers to choose a diesel car.

Modern petrol engines also use a diesel particulate filter system, known as GPF. But these are not subject to clogging. A petrol-engined car can therefore cope much more easily with short urban journeys. As you can see, driving is the best therapy for preventing catalytoc converter or diesel particulate filter problems.

Keep an eye on your car's health

It's important to keep your car well maintained. This means, of course, an annual service, including oil changes and a general check-up.

You should also be alert to certain symptoms that could indicate the beginning of a problem with your diesel particulate filter and/or catalytic converter. These could include more regular stalling, loss of power, abnormal noises or an increase in fuel consumption.

As our cars become more and more technologically advanced, it can also be the failure of a sensor that has more serious consequences in the medium and long term. For example, a worn lambda sensor needs to be replaced quickly.

By keeping your car well maintained, you can greatly reduce the risk of breakdowns. Better still, you can anticipate a potential breakdown.

Another valuable clue is to study your technical inspection reports, particularly the pollution measurements. If you notice that the limit values are approaching, it's a good idea to have your car checked.

By carrying out these checks in advance, you can quickly detect any problems that could worsen over time. Better still, it may avoid having to replace an anti-pollution device such as the catalytic converter or even the diesel particulate filter.

Clean the DPF and catalytic converter

It's also possible to clean the DPF by means of forced regeneration. These can be carried out at the brand's dealership. Of course, this is a temporary solution, designed to eliminate unburnt pollutant particles. It's a good idea to get into the habit of making more long journeys, so that cycles are triggered naturally when the car is sufficiently warm.

When it comes to catalytic converters, the ideal solution is to dismantle them, but this is a tedious and restrictive operation that requires equipment and expertise. Whether for a DPF or a catalytic converter, the simplest solution is still to use additives. There are a multitude of these available on the market, all of which help to extend the life of the DPF.

These additives are added at the same time as you fill up with fuel. This can have a temporary positive impact... But remember that the best remedy is to drive on the road long enough, maintaining an engine speed of at least 3,000 rpm.

Know how to analyse "worrying" symptoms

However, it's worth remembering that catalytic converters and diesel particulate filters wear out over time and lose their capacity. They sometimes need to be replaced, generally after 120,000 to 150,000 kilometres. These average figures should be put into perspective, however, because they depend enormously on your driving style and the initial quality of the equipment.

If your car doesn't run as well, if it's not as pleasant to drive, if the engine seems more "hesitant" and if fuel consumption is rising, it's time to have your car checked. And sometimes, a simple cleaning won't be enough. So don't wait until the last minute, or you risk damaging other peripheral equipment on your car.

Replacing a diesel particulate filter or catalytic converter is an operation whose cost can vary considerably. First of all, you should be aware that price does not always correlate with quality... And what's more, it's often the labour that adds to the cost.

After all, replacing this equipment involves lifting the car, dismantling part of the exhaust system, greasing it, reassembling it and then testing it. All this takes time and skill. However, even if the bill can sometimes reach four figures, it's necessary to ensure that your car remains in good working order for years to come.

The final word

When a problem is dealt with in good time, it's always easier to solve. This general truth also applies to catalytic converters and diesel particulate filters. By maintaining your equipment on a regular basis, you can greatly reduce the risk of breakdowns, even though no-one is immune to spontaneous failure.

But here again, the best way to prevent breakdowns is to drive your car as much as possible, over sufficiently long distances. This treatment limits wear and tear by regularly and effectively eliminating fine particles. As a result, your car's engine will be all the better for it in the long run.

Properly maintained, a diesel particulate filter can have an extended service life of over 200,000 kilometres. So don't hesitate when the opportunity arises: take to the road!

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Karolina Osinska / Author: grafvision / Licence ID: ZDTVJKS5W3 - elements.envato.com