MobileDPFCleaning – Central Virginia’s DPF & DOC Specialists
Heavy-Duty DPF & DOC Cleaning with the FSX Complete Cleaning System™
#1 OEM recommended Diesel Particulate Filter Cleaning Equipment in the world!
About Diesel Exhaust Fluid (DEF)
DEF does not contribute to cleaning the filters in any way whatsoever. It is injected into your system to improve emissions. Diesel exhaust fluid (DEF) is a new requirement on 2011 model year trucks using selective catalytic reduction (SCR) to eliminate NOx emissions.
MYTH #1: Regeneration Cleans the Filter Completely
Regeneration burns off soot but does NOT remove ash. Over time, ash buildup restricts airflow and can cause your truck to go into Limp Mode. Regular cleaning is required to remove ash and keep your filter functioning properly.
MYTH #2: The Warning Light Tells You When to Clean Ash
The warning light monitors regeneration, not ash buildup. If your truck is regenerating too frequently, it may be a sign your DPF is clogged with ash and needs cleaning.
Why Cleaning is Better Than Buying Cheap Replacements
Many low-cost DPFs sold online have little or no platinum group metals (PGM) coating, which means they regenerate less efficiently and clog faster. Our OEM-quality cleaning keeps your original DPF performing as intended — saving money and extending service life.
DOC Cleaning – The Overlooked Step
Your DOC (Diesel Oxidation Catalyst) is just as important as your DPF. If it’s dirty, contaminants will flow into your freshly cleaned DPF, causing premature clogging. That’s why we recommend testing and cleaning both the DOC and DPF together for best results.
Our Promise
We treat every filter like precision equipment — because it is. Careful handling, expert cleaning, and OEM-approved processes mean your equipment stays reliable, emissions-compliant, and on the road longer.
DOC – The Most Overlooked but Essential Part of Your Emissions System
Don’t Forget Your DOC
When customers call MobileDPFCleaning asking to have their DPF cleaned, our first question is:
“What about your DOC (Diesel Oxidation Catalyst)?”
Most people focus only on cleaning the DPF, but the DOC plays a critical role in your emissions system.
The DOC is an inline component in the after-treatment system — a flow-through filter coated with precious metals. Its job is to begin the oxidation process of hydrocarbons, carbon monoxide, and unburned fuel and oil before the exhaust gases reach the DPF.
Anything the DOC doesn’t fully oxidize flows directly into the DPF, where it collects and causes buildup.
Your DOC gets dirty too — and often dirtier than you think. Cleaning only the DPF can lead to a freshly cleaned filter getting contaminated again too quickly. That’s why we recommend testing and cleaning both your DOC and DPF to ensure maximum service life.
Understanding Your DOC (Diesel Oxidation Catalyst)
When customers call DPFilterFIX asking for a DPF cleaning, we always ask:
“What about your DOC?”
Most people focus only on the DPF, but the DOC is just as critical.
What the DOC Does:
The DOC is an inline, flow-through device containing precious metals that starts the oxidation process for hydrocarbons, carbon monoxide, unburned fuel, and oil — think of it as the pre-filter in your after-treatment system.Why It Matters:
Anything not oxidized by the DOC ends up in the DPF, where it accumulates. Over time, soot, ash, and by-products adhere to the walls of the DOC, restricting airflow and reducing efficiency.
Bottom line: The DOC gets dirty too — sometimes very dirty — and needs cleaning.
When to Clean Your DOC
Situations vary, but cleaning only your DPF may shorten service life if the DOC is still dirty. Residue from a clogged DOC can quickly re-contaminate a freshly cleaned DPF.
Signs you should consider cleaning both:
DPF re-clogs shortly after cleaning
Increased backpressure
Engine going into Limp Mode
Upstream issues like a bad turbo or leaking injector
Best Practice:
We recommend testing airflow in both the DPF and DOC before cleaning. This ensures both components are performing at peak efficiency.
Handling & Removal Tips
Your DOC and DPF are expensive, fragile components. Treat them carefully:
Remove units gently and avoid dropping them.
Remove all sensors before sending in for cleaning.
Pre-soak bolts and bungs before removal to avoid damage.
Avoid hammering, bending, or prying — think of your DOC/DPF like fine china.
Damage such as cracks, fractured ceramic, broken sensors, or bent flanges can cost thousands to replace. Careful handling saves money and downtime.
Preventive Maintenance & Limp Mode
Nothing grabs your attention faster than your truck going into Limp Mode (5 MPH limit). Preventive maintenance helps avoid this:
Keep a spare set of clean DPF/DOC filters ready.
Clean filters using OEM-approved systems like FSX Complete Cleaning System™ to maximize service life.
Understand your acronyms:
DOC = Diesel Oxidation Catalyst
DPF = Diesel Particulate Filter
DEF = Diesel Exhaust Fluid
REGEN = Engine Regeneration (removes soot but not ash)
ECU = Engine Control Unit