Introduction

Fleet managers and diesel owners are always looking for easier ways to keep DPFs clean. Products like Carbon B Gone market themselves as chemical solutions that “break down carbon and ash.” In some of their own wording, the claim goes further: the ash filling up your DPF will simply “go away.” That is a bold claim, because while soot can burn away during regeneration, ash cannot, and trying to force it out with chemicals risks creating new problems.

Carbon vs. Soot: The Distinction Matters

• Elemental carbon: Carbon atoms themselves cannot be destroyed or dissolved. They are among the most stable building blocks in nature. Diamonds are carbon, and no bottle of liquid is going to make carbon vanish.
• Soot: The material that accumulates in a DPF is soot, a mixture of unburned hydrocarbons and carbon fragments. During an active regeneration, high exhaust temperatures (about 600 °C / 1,100 °F) and oxygen bond with carbon, turning it into CO or CO₂ gas. That is why a regen restores some filter capacity: soot is oxidized and carried out in gaseous form.
  Catalysts: To be fair, a chemical additive might act as a catalyst, lowering the temperature needed for soot to oxidize. But that does not make soot disappear. It only changes form, the same way it does during a normal regeneration.

Ash: The Unmovable Residue

Ash is different. It comes from oil additives and fuel impurities and is made of stable minerals such as zinc, calcium, and phosphates. Ash is already fully oxidized and cannot be burned away or dissolved.

Instead, ash packs itself into the DPF’s cells, with about 200 cells per square inch in a typical filter. Once those cells start filling, no amount of chemical magic makes that material vanish. Adding liquids of any type (even water) directly into your emissions system while it is still installed on the truck can create a mud-like slurry that may clog the tiny filtration pores in the DPF even worse. While it is likely that the slurry will remain trapped in the DPF, if any does make it through, it can end up fouling downstream components like the DEF decomposition chamber, the catalytic elements of the SCR, or even the NOx and particulate matter sensors.

What Really Happens in a Regen vs. With Ash

Sintering, The Silent Filter Killer

• What it is: Sintering happens when leftover ash fuses together during repeated high temperature regens, forming hard, glass like deposits.
• Why it matters: Once sintered, ash cannot be loosened or flushed out. Those fused deposits permanently block DPF cells.
• The impact: Higher backpressure, reduced fuel efficiency, shorter filter life, and earlier replacement costs.
• The fix: Only a full, off truck service with controlled FWIE, SAVE, PWAF, RTTR, and final testing can prevent sintering and keep filters performing like new.

The DPF Guys Cleaning Process

The only proven way to remove ash is through a controlled, step by step service process. At DPF Guys, that means:

1. FWIE (Flow, Weight, Inspect, Evaluate) – Every filter and related part is inspected off the truck to ensure there are no cracks, breaches, or failures that would make cleaning ineffective. This step includes objective flow testing in inches of water column and precision weighing down to 0.0352 oz to establish a baseline of both flow efficiency and weight. The same process is repeated after cleaning, and the before and after results are fully documented and provided to the truck owner or fleet for their maintenance records.
2. SAVE (Sealed Air Vacuum Extraction) – Performed in an environmentally sealed air/vacuum blast machine that prevents soot and ash from escaping into the environment and protects workers from exposure. Compressed air and vacuum are used together to loosen and extract loose ash and soot from the DPF cells. The system provides real time visual feedback, allowing trained cleaning technicians to monitor the process and ensure the filter is not removed until the SAVE stage is fully complete. This first stage prepares the filter for wet cleaning without risk of compacting material.
3. PWAF (Pure Water Aqueous Flushing) – A chemical free flush using carefully controlled pressure and gallons per minute (GPM) flow rate. The key is that this process pushes ash and contaminants out of the DPF cells, not through the DPF, which is physically impossible since ash particles are much larger than the microscopic pores of the ceramic substrate. Leaving residue in the filter, either from chemical on truck cleaning or incomplete compressed air blow out, risks sintering, the permanent fusing of ash during repeated high temperature regens.
   Drying cycle – Ensuring the filter is completely moisture free before oven treatment.
4. RTTR (Ramped Temperature Thermal Regeneration) – Controlled baking with a gradual ramp up and ramp down in temperature to oxidize any trace hydrocarbons remaining in the filter cells or embedded in the pores of the filter walls. This process ensures the ceramic substrate is fully cleaned and conditioned for service, while preventing thermal stress from improperly controlled heating that could otherwise cause cracking or damage.
5. Final SAVE – After the filter has been cooled back down to a safe temperature, a second round of sealed air vacuum extraction is performed to remove any residual ash left in the filter after the oven process. This step ensures the filter is restored to as clean, or as close as possible, to its original condition so it can provide another 250,000 to 300,000 miles of service life before needing attention again, just like new.
6. FTR (Final Testing and Reporting) – Repeat the same flow testing and weighing performed in Step 1 to confirm restoration. Results are documented and supplied to the customer, providing a verifiable service record for compliance and preventative maintenance.

Why “Go Away” Is the Wrong Claim

It is true that soot goes away during a regen, because it changes into CO₂ gas and exits with the exhaust stream. Ash, however, does not behave that way. It does not burn, it does not vanish, and it certainly does not empty itself out of the filter on its own.

So when marketing says the ash filling up your DPF will just go away, that is not a simplification, it is a fundamental contradiction of how emissions systems actually work.