DPF - chemical cleaning

[ducnick]

Just wondering if anyone has experience of cleaning DPF’s to remove the ash, thus reducing the time between regeneration and in theory extending the life of the car.

I have a 2019 Audi q7 diesel and it’s done 70k miles. After a regeneration the DPF goes from 100% full to 22% full. I can’t get it to drop under 22% now (even after a motorway run to Bordeaux and back). I’m wondering if it’s worth having the DPF chemically cleaned now to remove the ash that’s built up. Would that restore it to as new condition and give me more miles between regenerations? I don’t fancy forking out for a new DPF and this vehicle is a keeper.

Does anyone have any good or bad experiences with chemical cleaning/flushing ash out etc?

Edited by ducnick on Friday 25th October 10:36

Edited by ducnick on Friday 25th October 20:50

[Belle427]

If the car is performing as it should then leave it alone, maybe consider adding one of the better treatments recommended here to the tank for peace of mind now and again or when you intend to do a long run.

[helix403]

I’ve had two cleaned off the car by dpf clean team. They come back as new with a chart documenting the flow.

[LordLoveLength]

The 22% full figure may be a bit misleading. The DPF fills with soot, the back pressure across it is measured and when it is above a certain level a regeneration cycle burns the soot off. There will be a small ash residue which does not burn.
The ECU counts the number of regeneration cycles and calculates the ash content. This is not a measurement. When the DPF is calculated as full, it will always show as full even if it is clean and has low pressure across it.
If you remove the DPF and have it properly cleaned (heated up and the ash blown out) you would still need to reset the ECU (tell it the DPF has been replaced) to clear the 22% to zero.

[KingGary]

I use STP dpf cleaner. Works wonders on my wife’s Focus ST. Worth a go at only £9 per bottle?