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Maintenance of the DPF

Posted: Fri Feb 20, 2026 12:15 pm
by zafershoukat3109
On my pegeout 2015 1.6 BlueHdi, I keep getting warnings about the DPF being clogged. I've cleaned it a few times, but the notice keeps popping up after a few days. There are 46g of deposits in the FAP, 90% of the cinders have been counted, and there are 0km of FAP life remaining. Even though I think some of these are computed, I find the 150 mbar+ pressure disparity at 3000 revolutions to be somewhat high.
Since replacing it isn't in the budget, we're considering removing it from the vehicle to clean and backflush it better.
Would backflushing still be an option or would I need to open the box, remove the DPF filter core, reinstall it, and then weld the box back together because the unit is a combined SCR\DPF? Will a MOT tester believe me if I choose the second option, or will they simply assume the DPF is gone?



Obviously, a DPF delete is another option; I get the ethical and legal concerns, but has anyone in the UK gone through this procedure and can speak about MOT smoke testing and anything else?

Many thanks

Re: Maintenance of the DPF

Posted: Fri Feb 20, 2026 12:15 pm
by tonysoprano
When you cleaned the DPF, what method did you use? Did you use an appropriate diagnostic tool to "tell" the car that a new DPF had been installed, assuming you cleaned the DPF and didn't merely try another regeneration?

To what extent has the car been driven?

Re: Maintenance of the DPF

Posted: Fri Feb 20, 2026 12:16 pm
by zafershoukat3109
You have my gratitude for your response.

Experimented with spraying both Wynn's Off Car fluid and Mannol DPF aerosol into the SCR\DPF housing through the pressure sensor port halfway along its length. Although their effects were temporary, they did lower the pressure disparity. The metal pipe that originated from the same port as the caked-up one has also been cleared!


I have a Diagbox and used it to perform a forced regen, but I didn't inform the car that it had a new DPF. The mileage is 139,500, which is supposedly the "programmed" life of the DPF. So, I understand that this won't help. I should clarify that I will address the fact that my initial attempt was unsuccessful at a later time. My suspicion is that the filter is still clogged and requires a more comprehensive cleaning because the pressure differential has gone straight up again.

I should mention that I'm experiencing exhaust blowback through the Adblue injector. I believe this is a result of gases taking the easiest route through the system, which is being clogged.

Re: Maintenance of the DPF

Posted: Fri Feb 20, 2026 12:17 pm
by tonysoprano
Firstly, I'd want to point out that the Wynns are meant to be used off the car and not in place. Although I am unsure if that pipe is optimal, the Mannol should have been effective.

Re: Maintenance of the DPF

Posted: Fri Feb 20, 2026 12:17 pm
by tonysoprano
A video of someone applying Mannol foam (or some other kind of foam) to an automobile was shown to me on YouTube. O'Rileys Autos, I believe it was. What you're describing—pressure blowing back through the Adblue injector—is exactly what I saw in another video. Additionally, that could have been O'Rileys Autos. Probably the identical video! They (or it) may be located by me.

Re: Maintenance of the DPF

Posted: Fri Feb 20, 2026 12:18 pm
by zafershoukat3109
This thread I shared recently includes a video demonstrating the blowback problem 😁, which you might be considering.

Re: Maintenance of the DPF

Posted: Fri Feb 20, 2026 12:19 pm
by tonysoprano
Aw, yeah, that was it.

I did come across this video where O'Riley cleans the DPF and then adds more Eolys/PAT fluid. An added plus is that it is mounted on a 308.

Re: Maintenance of the DPF

Posted: Fri Feb 20, 2026 12:19 pm
by tonysoprano