What is a DPF system


What is a DPF system

Author: SPELAB Mechanical Engineer (focusing on car modification for 10 years)

DPF stands for Diesel Particulate Filter to start. The DPF system, or diesel particulate filter, is a filtration system created to catch soot and stop it from leaving your diesel engine's tailpipe and entering the atmosphere. 

What is a DPF system

Modern diesel engines now include EGR systems and low-sulfur highway diesel to help cut back on dangerous NOx emissions. As a side effect of these systems' ability to lower exhaust temperatures, more unburned soot is now leaving the tailpipe. The DPF system was created to get rid of any soot that gets into the air.

How does the DPF system trap soot that is accumulated?   

DPF filters are typically constructed of a ceramic substrate in the shape of a honeycomb, which can filter out minute soot particles without impairing the exhaust flow significantly. Soot particles will no longer be trapped when the filter is full and the limitation level is too high. The filter then goes through a regeneration, often known as regen, procedure. Soon, we'll go into greater detail on this.

What parts are in the DPF system

While certain automotive systems make use of distinct technology, a DPF system will have a few components that are essentially universal across all heavy-duty trucks; however, we won't concentrate on these in this blog post. The principal parts of a DPF system are

  1. DPF filter (Diesel Particulate Filter)

  2. Diesel oxidation catalyst (DOC) filter

  3. Dosing injector 

  4. DPF pressure differential sensor

  5. Multiple exhaust gas temperature sensors

  6. EGR system 

  7. Turbocharger

The manufacturer has designed each of these parts to function as a unit in order for the DPF system to function as intended.

 How does a DPF regeneration work?  

What is a DPF system

The DPF filter's temperature is raised during this procedure until any accumulated soot is burned off. The soot is reduced to microscopic ash particles during this process. Since these ash particles are so substantially smaller, the restriction is released, restoring your exhaust flow.

The engine, EGR, and turbocharger all work together during regeneration to raise exhaust temperatures. The dosing injector is turned on once exhaust temperatures are at their ideal level. The oxidizing catalyst receives the heated exhaust gas together with the diesel that the doser (often referred to as the seventh injector) has injected into the exhaust stream. Extreme temperatures are built up as the exhaust stream enters the DPF filter itself due to an interaction between the diesel and hot exhaust gas caused by the catalyst's composition. It is hot enough at this severe temperature to burn the soot and turn it into ash. The DPF filter still traps the ash, but because of how much less of it there is, the exhaust flow can almost reach pre-regeneration levels.

The DPF pressure difference sensor and exhaust gas temperature sensors keep an eye on everything while it's going on and communicate to the engine or after-treatment computer how the DPF system is doing. You will notice a Check Engine Light (CEL) or a regen light that remains on if there is a failure. Knowing what causes a failure is crucial since, if the system is malfunctioning, this could result in additional downtime. If you are having trouble with a parked regeneration, see this subject we wrote.

 How long will regeneration last between service intervals? 

 You might be wondering where the ash goes now that we have established what the components are, how they capture soot, and what the regeneration process entails.

The ash is still lodged in the DPF filter and will ultimately accumulate to a point where maintenance is required. Several factors, like the state of your engine, how effectively you maintain its EGR system, and the type of operating conditions you are using, will greatly affect how long it takes to get to this position.

Compared to a truck operated largely on highways with almost little idle time, trucks operating in local areas or with considerable idle time will need service much more frequently.

Other parts of the system require upkeep on a more frequent basis. In general, replacing your seventh injector every 200–250k miles is a good idea, and getting your EGR system tuned up once a year. A little DPF system maintenance will go a long way toward preventing problems from arising.


With five cleaning facilities in strategic locations around the nation, the national travel center and diesel repair facility company TA/Petro (ta-petro.com) is able to fully restore both the DOC and DPF to like-new functioning conditions. They also offer delivery and pick-up services. You can take the parts out of the vehicle or farm equipment and have TA/Petro fix them. The total cost of cleaning the DPF is $350; the DOC only costs $49 to clean.

Four specialized pieces of equipment are needed to clean the DOC or DPF. An airflow test and component weighting are conducted first. The components are next baked in an application-specific oven at 1,000°F for roughly 12 hours with a computer-controlled cool-down rate, followed by a mechanical cleaning with air pressure and a special tool, a verification of the matrix's integrity with a lightbox, and a second flow test.

The TA/Petro service also replaces any necessary gaskets or clamps and repairs any worn or damaged mounting or sensor bungs. After being cleaned, the DOC and DPF are subsequently transported to your farm and are prepared for use.

You can maintain the functionality of all your equipment by utilizing services like these.


They are a DPF delete shop that provides expert DPF system cleaning. You can use the terms "DPF clean near me" or "DPF cleaning near me" to find their location.

They can restore any DPF, SCR, DOC, or EGR system to like-new condition with guaranteed results for a small portion of the price of a new system. Clean or you don't pay, guaranteed.

Who owns DPF alternatives?

Founder Junior Reyes

2013 saw the official launch of DPF Alternatives, thanks to founder Junior Reyes. Diesel Doc, Reyes' former business, served as the foundation for DPF Alternatives. Offering DPF filter cleaning is DPF Alternative.


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