A Mercedes diesel showing P2463, P2002, P0299, P0401 and P244A/P244B together looks scary — and a dealer will quote a £1000s DPF replacement. But most of the time the DPF is just blocked with soot, not dead. You can often clean it yourself and reset it with an iCarsoft CR Max P — exactly the job in the video below.
Those codes are all one blocked DPF. Read the soot/ash live data with a CR Max P: if it’s mostly soot (not ash), remove and flush the DPF, refit it, then force a regeneration and reset the counters. That fixes P2463/P2002/P0299/P0401/P244A/B for a fraction of a new DPF. Very high ash = replace instead.
- These six codes are symptoms of one blocked DPF, not six faults.
- Soot can be cleaned and burned off; ash can’t — the live data tells you which.
- After cleaning you must force a regeneration and reset with a scan tool.
- A DIY clean + CR Max P is a fraction of a dealer DPF replacement.
- Fix the root cause (short trips, EGR, pressure sensor) so it doesn’t re-block.
What the codes mean
They read like a disaster, but they’re all pointing at the same thing — a restricted diesel particulate filter (DPF):
| Code | Meaning | How it links to the DPF |
|---|---|---|
P2463 |
DPF soot accumulation (too much soot) | The headline — the filter is loaded up. |
P2002 |
DPF efficiency below threshold | The ECU can’t verify the DPF is working. |
P244A / P244B |
DPF differential pressure too low / too high | The pressure across the filter is out of range — blockage or a bad sensor. |
P0299 |
Turbocharger underboost | High exhaust back-pressure from the blocked DPF chokes the turbo — hence the power loss. |
P0401 |
EGR insufficient flow | Often tags along with a clogged exhaust/EGR path. |
Why they appear together
It’s a chain reaction. Soot builds up (P2463), so the differential pressure climbs (P244A/B) and the filter can’t pass its efficiency check (P2002). The extra back-pressure starves the turbo (P0299) and upsets EGR flow (P0401). Clear the blockage and the whole set usually clears with it — which is why cleaning the DPF is the fix, not chasing each code.
Clean vs replace — where the saving is
A dealer’s answer is often a new DPF, which on a Mercedes runs well into four figures with labour. But a DPF only truly needs replacing when it’s full of ash (the non-burnable residue that builds up over the filter’s life). If it’s mostly soot, it can be cleaned and regenerated — and that’s a job you can do at home.
Reading the live data (the key step)
Before you touch anything, plug in the CR Max P and read the DPF live data. The numbers tell you whether to clean or replace:
- Soot content (model & simulated) — high soot cleans and regenerates well.
- Ash content — very high ash means the DPF is worn out; cleaning won’t save it.
- Differential pressure across the DPF — shows how restricted it is.
- Exhaust temperatures upstream of the turbo, cat and DPF — needed for regeneration.
What you’ll need
- An iCarsoft CR Max P (DPF regeneration + live data).
- An oxygen/pressure sensor socket set.
- DPF cleaning fluid and something to flush it through.
- Jack, stands and basic exhaust tools; new gaskets and a DPF pressure sensor if needed.
Watch the DIY clean
Video credit: Save £1000s Fix DPF P2463, P2002, P0299… Yourself DIY, by SA Diagnostic’s. Independent third-party demonstration.
Step-by-step
- Scan & read live data. Plug in the CR Max P, confirm the DPF codes, and note soot, ash, differential pressure and exhaust temps.
- Remove the sensors and DPF. Undo the DPF pressure/temperature sensors with a sensor socket, then remove the DPF from the exhaust.
- Clean the DPF. Flush it with DPF cleaning fluid until it runs clear, removing the trapped soot.
- Refit everything. Reinstall the DPF and sensors with new gaskets; fit a new DPF pressure sensor if the old one is suspect.
- Regenerate & reset. Run a forced DPF regeneration and reset the soot counters with the CR Max P.
- Verify. Re-check live data (soot and differential pressure should be low), clear the codes and road test.
Cost saving
This is why the video is called “save £1000s”:
Related guides
Frequently asked questions
Can I clean a Mercedes DPF instead of replacing it?
What do P2463, P2002, P0299, P0401 and P244A/B mean together?
How do I know if my DPF can be cleaned or needs replacing?
Do I need a scan tool to fix a DPF myself?
How much can I save doing it myself?
Will the codes come back after cleaning?
Disclaimer: General guidance — verify the exact procedure for your Mercedes model and engine, and follow local rules on DPF work (the DPF must remain fitted and functional). Exhaust and DPF work carries risk; if unsure, use a qualified technician. The embedded video is an independent third-party demonstration. Prices are estimates accurate at the time of writing.
