Diesel Particulate Filters (DPFs) have been around for more than 25 years. Initially designed for large diesel engines, they became mandatory for all diesel-powered vehicles starting in 2009 due to stricter emissions regulations.
When a DPF fails or reaches the end of its service life, replacement is essential—not only to pass emissions testing but also to restore your engine’s performance. One alternative, where legal, is to install a DPF delete and muffler delete exhaust system, which can improve engine efficiency, add horsepower, and deliver a more aggressive exhaust note.
How a DPF Works in Short
As the name suggests, a DPF works like a filter, but it’s a little more complex than that. Simply put, they trap the burned diesel particles resulting from the engine combustion and allow the gases to pass through.
The DPF’s control module and some sensors can detect when it’s full and are in constant communication with the vehicle’s engine computer. When a set of conditions are met, the DPF burns the accumulated contaminant particles, turning them into CO2 and water vapor, cleaning itself and restoring the exhaust’s efficiency. This process is known as ‘regeneration’ and helps keep the DPF clean and running effectively during its lifetime.
There are three types of regenerations. Let’s take a quick look at them:
- Passive Regeneration: This occurs when soot is naturally burned due to high exhaust temperatures. It often happens when you drive the vehicle, for example, on a motorway at a speed of over 45 mph for 15 to 30 minutes, depending on the model.
- Active Regeneration: When you drive your vehicle in the city, the DPF doesn’t get enough heat or time to regenerate properly. The engine computer will detect that the DPF needs regeneration or trigger one at a preset mileage (around every 300 miles). How? Using a process of post-combustion injection or by modifying the air/fuel ratio to increase the exhaust temperature to the point it can burn all the soot away.
- Forced Regeneration: Repair shops use this process to try to save an aged DPF that fails to regenerate. They use a professional scan tool and follow a procedure that involves heating the exhaust to extremely high temperatures as a last attempt to unclog the DPF before replacing it.
A Brief Intro To Aftermarket Parts
Aftermarket parts are sold as a cost-effective alternative to the original components you can get at your vehicle brand’s dealership. Original parts can be over three times more expensive than some aftermarket parts. There are some misconceptions about stock replacement parts that are worth clarifying. That’s why we will classify them into three categories and bust some myths.
OEM Parts
OEM (Original Equipment Manufacturer) spare parts are made by factories that provide components to automotive terminals. Most companies also sell these components to the general public using their own branding, ensuring they are of the same quality as the original parts.
Unfortunately, this is not always the case. Some brands provide parts to vehicle factories but sell OEM parts that might not go through the same strict quality tests as their original counterparts.
In addition, some OEM parts may cost more than the original due to distribution or import expenses, low production volumes, or revised versions, among others.
Alternative or Generic Parts
Unlike OEM parts, alternative or generic parts are not made by the same company that makes the original ones. Some are good quality and made by trustworthy companies that also make original parts for other vehicles. Sadly, you can find many low-quality replicas in this category, giving aftermarket parts a bad reputation.
It’s important to note that not all alternative/generic parts are the same. While alternative parts are often cheaper than original and OEM ones, really cheap ones might be suspicious. When in doubt, ask an expert or your trusted mechanic. It's better to spend a few more bucks than deal with problems later on.
High-Performance and Tuning Parts
High-performance parts and tuning parts also fall in the aftermarket parts segment, as they are not often made by the vehicles’ manufacturers. Even if they did, they don’t initially come with the stock vehicle, hence the “aftermarket” label.
In this category, you will find thousands of brands making all kinds of products, from engine tuning parts such as big turbo kits, high-flow intakes, DPF delete kits, suspension upgrades, and others to aesthetic improvements like rims, LED headlights, racing seats, and much more.
Aftermarket DPFs
A DPF can fail for several reasons, but depending on driving habits, it usually has an average lifespan between 80,000 and 150,000 miles.
DPFs, like catalytic converters, are expensive parts, and many people consider replacing their DPFs with an aftermarket due to their tempting reduced price tag.
Let’s see some important things to consider when choosing between an aftermarket or an original DPF.
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Fitting: If you choose to go for an OEM DPF, fitting is usually not a problem because they are made using the same matrix as your original PDF. When choosing a generic or alternative one, try to get as much information as possible. Some cheap DPFs have some annoying fitting issues. For example, some low-end products’ bolt holes do not align with the turbo’s mounting bolts. Others have poorly finished flanges that cause leaking problems or won’t even hold a stock gasket, and you would need to use two gaskets or find a way to get a thicker one built. Other low-end models are slightly bigger than the stock unit, making installation almost impossible.
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Operation: Most aftermarket DPFs work well, even when they are hard to install. However, it’s important to be aware of some poorly engineered products that don’t function as they should. For example, some aftermarket DPFs fail to build enough heat to regenerate regenerate successfully. That renders them completely useful, making the engine constantly run in emergency mode, plus the hassle and extra expense of finding a way to solve the problem or get another unit.
A good-quality aftermarket DPF should work just like the original. Some aftermarket DPFs serve their purpose well but get clogged more quickly and need to be regenerated more frequently due to poor design or the use of smaller filters than the original ones.
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Durability: An aftermarket DPF should last the same as the original one. Its durability depends on its construction, materials, and manufacturing process. It’s essential to purchase a product with a good warranty or from a reputable brand.
- Installation: Removing and installing a DPF is difficult in most vehicles. Not because it requires much knowledge but because they are bulky and often placed in hard-to-reach places. Some original DPFs are bolted to the turbocharger and the rest of the exhaust; others are fastened to the downpipe and the rest of the exhaust, and some models are integrated into the exhaust. To replace the integrated DPFs, it’s necessary to cut the exhaust and weld the new DPF back in. If your stock DPF is bolted, choose a model that doesn’t require cutting the exhaust’s original flange and welding. This is not only a terrible design and makes the installation process more complicated, but it also makes it evident to a trained eye that the DPF has been replaced by a low-quality one, which may affect the vehicle’s retail value, among other things.
High-Performance Exhaust With DPF and Muffler Delete
If your DPF dies and you want to solve the issue and pamper yourself, consider replacing your vehicle exhaust system. There are different types of aftermarket exhaust systems. They come in different diameters and noise levels.
If you choose to go that way, you can get rid of the troublesome DPF, tune your engine’s computer, and get a muffler delete, all in the same package. A high-quality aftermarket exhaust system will fit your engine like a glove, and you won’t have to worry about misaligned bolt holes or other issues.
Before installing a high-performance exhaust, check your local emissions regulations and see if it’s legal to delete your vehicle’s emissions in your area. Also, check your local laws about muffler deletion. In some cases, removing the DPF is only allowed for racing vehicles or off-road use only. However, regulations tend to be less demanding for muffler delete kits.
Final Thoughts
Many people are afraid of the quality and performance of affordable aftermarket DPFs because they assume that quality and price are related. However, the manufacturing cost of a DPF is less expensive than that of other components. Many vehicle manufacturers are choosing new DPF brands that work extremely well.
However, as always happens with original parts, sometimes you end up paying comparatively more for the brand than for what’s inside the box. In the end, DPFs are serviceable parts, like the rest of the vehicle's filters. It’s just a question of researching,
seeking expert advice, and buying a product with a good warranty and customer service. Just make sure that it fits well; your mechanic would appreciate it very much.
