Dpf delete kits

1 — How does it work

The DPF delete operates on a principle of storage / retrieval of particles in the filter, while allowing the exhaust gases to pass. It does not eliminate particles continuously because the temperature of the gases does not reach the 550 ° C required permanently, except during a highway route.

In the city, at a speed of 50 km / h, the temperature does not exceed 150 ° C. The ideal time to regenerate is defined according to the pressure drop (pressure difference between the inlet and the outlet of the filter), but also the soot accumulation conditions, the number of kilometers traveled, the average speed and the type of driving. Do not wait until the filter is too full to regenerate, as it may damage the DPF.

2- What are the different technologies?

The two systems on the market use post-injection in the combustion chamber to heat the gases and then the thermal effect of the precatalyst. The difference lies in the regeneration of the filter.

A — For the PSA FAP, it is the additive contained in an independent tank that represents the main innovation. Indeed, this mixture of iron oxide and cerium oxide, called Eolys, has a catalytic effect by mixing with soot. It releases oxygen to the heart of each particle, which accelerates the combustion by lowering the burning temperature of the particles by 100 ° C, ie 450 ° C. Regeneration lasts no more than five minutes and limits overconsumption of fuel. Disadvantage, you have to refuel Eolys every 120,000 km and its life was limited to its beginnings.

B — On the oxidation filter, it is not an additive that facilitates the burning of particles but the internal walls covered with precious metals (platinum …) and which have a catalyst effect on accumulated soot. But it induces very high temperatures (about 650 ° C) to trigger regeneration, which remains the weak point of this system in the context of urban use. In addition, the regeneration is longer (15 to 20 minutes), resulting in high consumption.

In addition, this regeneration is sensitive to driving conditions and may be incomplete, which clogs and damages the filter. To solve the regeneration problems in the city, Renault and Toyota have added a fifth integrated injector to the exhaust line. When a sufficient amount of soot is detected in the FAP, fuel is injected into the exhaust gases causing their temperature to rise (above 570 ° C).

The filter placed right behind uses this heat to improve the destruction process of the stored particles. Advantage: the regeneration process no longer depends on speed, engine speed or travel time. It works even when the engine is idling in the city and in traffic jams. Only mounted on the 1.5 dCi (due to a patent case with Toyota), this system is no longer in effect on the Euro V version, with Renault relying on the post-processing of its new injection system.

3- What is a regeneration?

It is similar to chimney sweeping, which must be cleaned regularly to avoid clogging. There are three types of regeneration:

A — The spontaneous. This is the ideal scenario when driving conditions directly influence the temperature of the exhaust gases and consequently the particles that burn naturally in the filter. However, the thresholds established to activate cleaning are difficult to reach under normal driving conditions.

B — The ordered. It is driven by the engine ECU which aims to increase the temperature of the exhaust gas by various means: cut gas recirculation (EGR), control the turbo to maintain the engine torque and activation of the post-injection.

C — The forced. It is only applied by network workshops from a diagnostic tool that measures the percentage of clogging. In addition to cleaning the filter, the engine oil and the oil filter are replaced and the engine computer is reset. For example, for a Renault Scénic II 1.5 or 1.9 dCi, the operation is invoiced between € 220 and € 250. 4 — Should we replace it and how often?

This is the big advantage of non-additive FAPs: their theoretical lifetime corresponds to that of the vehicle. However, longevity depends on several factors: driving style (road or city …), frequency of regeneration, quality of maintenance … which cause clogging and premature replacement.

At Audi, for example, a control is recommended between 150,000 and 210,000 km depending on the engine. The result is often to advise the replacement. As for the FAP with additive, everything depends on the year of the vehicle. Indeed, several generations of FAP have succeeded

at PSA. Until November 2002, the service life did not exceed 80,000 km. This limit reached, a second generation of additive (Eolys 176) makes it possible to postpone the deadline to 120 000 kms. In 2003, PSA launched a FAP with a honeycomb structure capable of storing more particles. Today, the replacement ranges between 140,000 and 210,000 km depending on the engine.

5- Is it maintenance free?

For the oxidation FAP, no intervention is recommended, if not a control. Nevertheless, the operation of this type of filter generates a phenomenon of dilution of the oil, that is to say that the surplus unburned diesel fuel mixes with the lubricant during the post-injection phase. The quality of the oil can then deteriorate rapidly, hence the reduction of the inspection intervals.

The engine calculator analyzes the oil and as soon as the threshold is exceeded, the oil indicator acts as a guardrail. As a result, the use of a specific oil is mandatory. As for the additive FAP, the maintenance consists in carrying out a supplement of Eolys every 120 000 kms. 6 -What are the main damages?

The most common is the lighting of the indicator light and the switch to degraded mode of the engine (lower performance) related to filter clogging.

The solution goes through a forced regeneration workshop, or even by replacement. But that’s not all. The dilution of the oil and the degradation of its quality lead to poor lubrication of the turbo with the risk of damage. In addition, the increase in the oil level can be the cause of runaway engine and cause a break pure and simple.

However, the filter damage also depends on other causes: malfunction of the thermostat, flowmeter, injectors, presence of oil in the intake circuit, turbo problems or the EGR valve … A real headache for them. repairers. 7- How much does it cost?

Although their lifespan is long on paper, a replacement FAP is very expensive. This remark mainly concerns buyers of a second-hand vehicle who, for lack of knowledge, miss the presence of a particle filter. Except that the reliability of the latter, depending on the kind of use but also the maintenance, is hardly appreciable. Therefore, the premature replacement of a filter can represent a significant sum in relation to the value of the vehicle.

Fortunately, PSA reduces the bill thanks to the standard exchange. Good news, the exchange market is investing in the sector: Walker, a specialist in the FAP, is expanding its aftermarket catalog, and Bosal Distribution is offering PSA references in standard exchange.