What is a Diesel Particulate Filter (DPF) and how can it affect your diesel vehicle?
A Diesel Particulate Filter (DPF) is an emission saving/emission control device fitted with increasing frequency to diesel vehicles - starting with vehicles manufactured in 2007, almost all newly released passenger diesel vehicles sold in Australia will now come fitted with a DPF. Designed to protect the environment from excess pollution, the DPF system was created with the intent of capturing up to 90% of harmful byproducts resulting from the operation cycle of a diesel combustion engine. The DPF is commonly located centrally underneath a vehicle and makes up a small component of the vehicles exhaust system and is a sealed unit.
The DPF system captures elemental carbon particulates (commonly referred to as soot) during normal operation. The most common issue that arises with DPF fitted vehicles is the vehicle going into limp mode due to the filter filling with these particulates. Any type of filter has a limited capacity for capturing particulates so the DPF will eventually reach maximum capacity, in turn causing an increase in exhaust gas pressure due to flow restrictions. This restriction would negatively impact the engine output and long-term life expectancy of the engine. Therefore, diesel particulate filter systems require a way of removing particulates from the filter to restore the ability of the filter to continue to collect soot.
This removal of particulates, known as filter regeneration, can be performed either continuously during regular operation of the vehicle, this method is known as passive regeneration and occurs once the vehicle has reached optimal operating temperature and is driving at a constant speed for example highway driving. The other method of filter regeneration is periodically after a pre-determined quantity of particulates have built up in the filter usually around 40-50% of the filter capacity, the Engine Control Unit (ECU) will then increase the operating temperature of the vehicle and in turn the exhaust to facilitate the burn off of the built up soot, this method is known as active regeneration. The specific method of filter regeneration for each vehicle model can be found in the owner’s manual.
What are the common issues with a DPF?
If a vehicle spends most of its driving time travelling short distances or in stop start traffic, often the vehicles exhaust will not reach the required temperature, or the vehicle won’t achieve the other required parameters to begin the filter regeneration process. Over time this means the filter will continue to clog until it begins to affect exhaust pressures, once this point is reached often the vehicle will come up with a warning light on the dash suggesting the vehicle should be taken on a decent drive on an open road, or taken to a dealership/mechanic to have the filter manually cleaned. If the filter continues to become further clogged beyond this point, the ECU will then put the vehicle into limp mode or limp home mode and will often not rev past 2500-3000rpm and the DPF will then need to be either cleaned or replaced by a qualified mechanic or dealership.
Replacing a DPF can cost thousands of dollars so it’s vitally important for any vehicle equipped with a DPF to avoid short distance driving and to be regularly driven on open roads or highways for the filter regeneration to take place.
How can United Fuel Injection help with DPF equipped vehicles?
Unfortunately, we are very limited in what improvements or protections we can provide for vehicles with DPF’s due to the laws surrounding vehicle modifications and vehicle emissions.
We can fit exhaust systems from the DPF back to provide small increases in power and torque but as the DPF is still present, so is the main point of restriction so the performance gains can be limited.
If you have a DPF equipped vehicle and want to discuss any of the options for performance gains, give us a call on (08) 9259 3000 and have a chat with our performance department.