DPF Ireland

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DPF Diagnostics

A DPF is a filter that reduces harmful particles generated by a diesel exhaust in vehicles from entering the atmosphere. This filter essentially catches harmful particles and burns them off when the engine gets hot enough, when you are driving on a motorway. Located within the exhaust system, the DPF may cause repeated problems when it gets blocked, resulting in expensive repair bills. It is thus essential to regenerate the DPF on a regular basis in order to avoid a complete blockage caused by a build up of particles.


How to Remove a DPF

In most countries, it is illegal to remove and not replace the DPF from a vehicle, even though it is actually possible to remove the filter physically. If you have removed the DPF filter from your car, you are likely to fail the annual inspection and you all will not pass an emissions test. Instead of removing the DPF, look for ways to prevent blockages such as DPF Cleaning and learn how to diagnose any possible faults and correct them as soon as possible to avoid further damage.


How to Clear a Blocked DPF

When soot builds up in the DPF, it will become blocked. To unblock it, you need to burn away the soot via a process called regeneration. Regeneration can happen in multiple ways, and all of them contribute to unblocking the DPF.

Passive regeneration: this type of regeneration naturally occurs when the vehicle gets hot enough, especially during long rise to high-speed on a motorway.

Active regeneration: your car initiates this process as a response to a blockage by injecting diesel on the exhaust stroke in order for it to ignite and burn the soot.

Forced regeneration: if the filter becomes very blocked and active or passive regeneration are no longer options for unblocking it, or if the car goes into limp mode, a mechanic may carry out a forced regeneration by burning the soot off. Keep in mind that this can only be done four times before damaging the filter permanently. Moreover, force regeneration is an expensive procedure.

Using DPF Cleaners: a quick and convenient way to keep your DPF working efficiently, DPF cleaners work by lowering the temperature the soot burns at, which means that you can clear the filter just by normal driving, not only when you’re driving on a motorway. This is an inexpensive and convenient way to keep the DPF working efficiently, and if you use it when the warning light comes on, you should expect it to go off in about 10 minutes. We stock two main DPF Cleaning Additives Pat Fluid and Bardahl. If you are looking to purchase any of these product please feel free to give us a call to discuss which best suits your needs.


Types of DPF Blockages

DPF blockages are not all the same and various stages of blockage require different treatment. When the light on your dashboard comes on, it means that the DPF has become blocked and at this stage, the blockage would be about 45%. This means that you don’t need the help of a mechanic to clear it. This is one of those situations where you can burn off the soot yourself by Passive Regeneration, as described above to burn away the soot. If you ignore the warning light and don’t take action, your car may get to the next stage, which is limp mode. If this happens, you will need the help of a mechanic to perform a forced regeneration, which could cost you hundreds of euros. Keep in mind that forced regeneration gradually destroys the filter, so you can only do it four times before the filter becomes permanently damaged.


How Much Does It Cost to Buy a New Diesel Particulate Filter?

DPFs are fairly expensive, and a new one for your vehicle can be anywhere in the range of €1,000 and €4,000. This high cost usually wipes out all the cost savings that are generally associated with driving a diesel. When it comes to older cars, the cost of replacing the DPF could be much higher than the actual value of the car. Higher mileage cars are likely to require a new diesel particulate filter.

When looking to replace the DPF of your car, it’s essential to shop around for the best prices, but keep in mind that even though there are other suppliers out there who charge less than our selves, they need to have the correct Type Approval. Purchasing from a non approved supplier may result in fitting the wrong type of DPF on your vehicle resulting in further repairs.

We supply new DPF’s and carry many in stock for the main manufacturer makes and models so we will ensure that you will be getting the correct DPF that suits your vehicle. We have invested a lot of research, time and money in having the correct systems in place to check compatibility. We also work very closely with local mechanics and can recommend them for fitting if needs be.


Engine Pressure Sensor Codes

You can determine the type of fault related to the DPF by having a look at the fault code on the filter. Here are some of the most common DPF fault codes:


  • P1471 – DPF regeneration not completed
  • P242F – DPF regeneration not active
  • P2002 – DPF efficiency below threshold
  • P2003 – Particulate mass is too high
  • P224B – Pressure is too high
  • P244A – Pressure is too low
  • P2452 – Pressure sensor malfunction
  • P2453 – Sensor malfunction
  • P2454 – Sensor voltage too low
  • P2459 – Regeneration frequency implausible
  • P2458 – Regeneration maximum regeneration time exceeded


How Do Mechanics Perform a Static Regeneration Procedure?

In order to carry out a static regeneration, a mechanic will generally position the vehicle outdoors on a suitable surface and initiate the regeneration process using a diagnostic tool. All mechanics need to observe strict safety procedures prior to and during the regeneration process.

Diagnostic tools allow mechanics to select a suitable program and then take the vehicle for a drive for about 20 minutes at a moderate cruising speed. The diagnostic tool initiates the regeneration and monitors the process from start to end so you can be sure the regeneration is complete at the end of the cruising. For safety reasons, a second technician will generally have to sit in the vehicle and observe the data provided by the diagnostic tool. If your vehicle has an additive tank, you need to be sure that the right amount of additive is present in the tank before starting the regeneration process. You should also make sure that there are no faults in the additive or in the fuel filler cap sensors to avoid any kind of damage.