DPF, or Diesel Particulate Filter, is a technology used to help clean the air. It’s especially common in cars that run on diesel fuel. Since 1985, many countries have passed laws that require the use of DPF in these vehicles. However, removing it has its own ups and downs, so this article details the DPF delete pros and cons.
Here’s how it works: When a car’s engine burns fuel, it can create something called “soot.” Soot is a kind of pollution that can make the air dirty. The DPF system in a car catches this soot and keeps it from getting into the air.
But what happens to the soot once it’s caught? The DPF system can actually burn it up. If the filter gets too full, a part of the car called the ECU raises the temperature of the exhaust, and the soot gets burned away.
There’s one thing to watch out for, though. If a car is stuck in traffic and the engine is running at a low speed, the DPF system might not work as well. This is something that experts are aware of and are working to improve.
DPF Delete Pros and Cons
For this article, we have consulted several industry experts and real user responses on relevant forums such as Reddit, Cummins, Ram1500Diesel, Quora, etc. That is to say that the information here on DPF delete pros and cons is like no other.
These are real-user information from people who have deleted their DPF at some point for whatever reason, whether for the fun of it or to trick their way out of emissions testing (though the likelihood of passing with a deleted DPF is slim these days).
The sections are divided into two to cover both the DPF delete pros and cons. We arrived at 9 pros and up to 14 cons of deleting DPF, making 23 findings.
Pros of Removing DPF
1. Better Fuel Mileage
Removing the DPF can lead to improved fuel efficiency. This means the vehicle can travel more miles per gallon of fuel.
The DPF system can restrict the exhaust flow, leading to less efficient fuel consumption. By removing it, the engine can breathe easier, leading to better mileage. This translates into significant fuel savings. Based on calculations, a delete could save around $4326 to $8000, depending on the mileage and fuel prices.
2. More Power and Acceleration
Without the DPF, the engine can produce more power and accelerate faster. The DPF can cause back pressure in the exhaust system, limiting the engine’s power. Removing it can unleash more horsepower.
3. Longer Engine Life
The DPF system can sometimes cause problems that may affect the engine’s longevity. Issues like clogging can lead to increased engine wear. Removing the DPF can prevent these problems, potentially extending the engine’s life.
4. Reduced Costs
DPF systems require maintenance and can be expensive to replace. If removed, you can avoid these costs. This is considered an economical decision that resolves the extra costs of DPF failure forever.
Through a DPF delete, some users have been able to stretch oil changes to 10-15K, saving more money and protecting the engine better.
5. Increased Performance
Some users have reported a modest increase in MPG and a reduction in emissions-related equipment malfunctions, making it seem like a win-win situation. Without the DPF, there’s a lower risk of filter clogging and other related problems, leading to increased reliability and potentially longer engine life.
6. Cost-Effective DIY Option
Some people have found that deleting the DPF themselves is a simple and cost-effective project, requiring only basic tools and some effort.
7. Enhanced Power and Sound
With a tuner, you can make massive power, and some tuners can make the engine sound like an older model, adding to the driving experience.
8. Better Reliability and Less Carbon Buildup
Deleting the DPF can lead to better reliability, less carbon buildup, and the freedom to choose different types of oil without worrying about the DPF’s life.
9. Good for Avoiding Problematic Parts
Another pro of a deleted DPF is that it gets rid of the “problem child parts” that are part of the emissions system. Some people have expressed satisfaction with the delete, mentioning very little smoke and a return to expected performance levels.
Cons of Removing DPF
1. Increased Air Pollution
The DPF’s main job is to reduce air pollution by trapping soot and particulate matter. Therefore, removing it can increase the amount of harmful emissions released into the air, contributing to environmental problems—a primary problem of DPF removal.
2. Legal Issues
In many countries, removing the DPF is against the law due to environmental regulations. If caught without a DPF, you could be fined or face other legal consequences. For example, these 11 men and 3 companies face federal charges for deleting emissions controls from hundreds of semi-trucks. But here are things you can do if caught with a deleted diesel.
3. Potential Damage to Other Components
Removing the DPF might lead to other unforeseen problems with the vehicle. The DPF system is integrated with other parts of the vehicle, and removing it might affect other systems or components. There are concerns about potential mechanical problems such as blown head gaskets from removing the emissions, specifically the EGR.
4. Greater Particulate Emissions
The DPF is designed to eliminate up to 99% of diesel soot emissions. Deleting it leads to greater emissions, which can have environmental and health impacts.
5. Social Perception
Rolling coal (emitting thick black smoke) can lead to negative perceptions from others on the road, and some users have reported being followed and confronted by other drivers.
6. Possibility of Smoke
Removing the DPF might lead to occasional smoke, depending on the mapping. While this might not be a significant issue for some, it could be a concern for others who are more environmentally conscious or worried about the appearance of their vehicle.
7. Remapping Requirement
If the DPF is removed, the vehicle will likely need to be remapped. This could be a deterrent for some owners, especially if they have already invested in a specific remap for their current setup.
8. Reduced Resale Value
One user shared an experience where dealerships refused to take a deleted truck on trade-in, stating that it was worth nothing. Restoring emissions equipment to a truck that has been deleted can be expensive, and selling a deleted truck is illegal in some jurisdictions.
9. Upfront Cost and Devaluation
Another user pointed out that the upfront cost and subsequent devaluation of the vehicle from the deleting process itself negate any potential fuel savings from deleting. Deletes are seen as good for performance but not necessarily financially sensible unless you plan to keep the truck forever.
10. Warranty Issues
Think about the potential warranty issues associated with deleting your DPF. If the truck is still under warranty, there are a few pros and many cons to deleting.
11. Complexity and Effort
Some users shared their experiences with the complexity of the delete process, describing it as a “major pain in the ass” and expressing concerns about reinstalling components for the sake of warranty.
12. Need for a Tune
To avoid warning lights and ensure proper functioning after a DPF delete, a specific tune is required. This adds complexity to the process and may require professional assistance, adding to the overall cost.
13. Potential Smog Test Failure
Depending on the state’s requirements for smog testing, the DPF delete may cause the vehicle to fail the test, requiring reinstallation of the DPF for inspection. Nevertheless, you may be able to pass smog with a modified vehicle.
14. Possible Compatibility Issues
There are concerns that performing a DPF delete to run the vehicle on 100% biodiesel might not be advisable due to the advanced fuel system’s inability to handle true biodiesel.
DPF Failure Symptoms
If your car’s Diesel Particulate Filter is not working right, you might notice some of these signs:
- Engine problems. Your car might lose power, and the engine might get really hot.
- Warning lights. Lights on your dashboard might come on.
- Bad smells. You might smell something sharp inside the car.
- Using more fuel. Your car might use more gas than usual (this is called a reduction in MPG).
- Slow response. When you press the gas pedal, the car might not respond quickly.
These problems can happen if the DPF isn’t cleaned out regularly.
Important Notes
- Blue smoke. If you see blue smoke coming out of your car, it might be burning extra fuel. If you see black smoke, your DPF might be broken, and you might need a new one.
- Oil problems. If oil gets into the DPF, it can hurt the engine and even cause it to fail. Fixing a broken DPF can be expensive.
Taking care of your DPF is really important to keep your car running well.
Types of DPF Systems
There are different kinds of DPFs that are used in cars. Here’s a table that shows the 3 most common types:
| Type | Name | Main Differences |
|---|---|---|
| Cordierite | Cordierite Wall Flow Filter | Common, different melting temperature and size |
| Ceramic | Ceramic Fiber Filter | Different melting temperature and size |
| Silicon Carbide | Silicon Carbide Wall Flow Filter | Different melting temperature and size |
There are other types of filters too, like metal fiber and paper filters, but the cordierite filter is the most common one. The main differences between these types are in how they melt and their size, which affects how well they work.
Conclusion on DPF Delete Pros and Cons
DPF delete, or the removal of the Diesel Particulate Filter, is a subject that brings both benefits and challenges. On the positive side, deleting the DPF can enhance engine performance, increase fuel economy, and lower maintenance costs. It can make the vehicle feel more powerful and efficient.
However, the cons are significant and cannot be ignored. Diesel soot, which the DPF is designed to filter, is a known cancer-causing agent – Centers for Disease Control and Prevention (CDC). The link between cancer and diesel combustion is well-documented, and government bodies have implemented emissions regulations with the intention of protecting public health.
The performance aftermarket, while currently mostly unregulated, is at risk due to abuses like the “Rollin coal” epidemic. This has led some manufacturers to pull certain products, and more states are likely to follow California’s strict lead. California’s mandatory inspections and regulations could become a model for other regions, leading to stricter rules and penalties.
Read also: How Can You Tell if a DPF Has Been Removed?
