Ciaran2 wrote ...

The DPF, will gradually fill up, even when going through regular regenerations (which it will be with your daily 40 mile motorway commutes).

When it reaches a particular point of 'fullness' (sensed by comparing the pressure differential between the sensors at the entry and exit points), the display will regularly report 'Risk of particle filter clogging', particularly if you accelerate or push the car hard.

You can mitigate this for a time by switching to a fuel with an integrated cleansing agent (such as BP Ultimate or Shell V-Power), this may yield some improvement or the problem may go away entirely. It can take a month to 6 weeks for the effects to be felt. 53,000 miles seems quite low for these symptoms but much of it depends on the cars usage, the type of fuel its been primarily run on, kind of journeys etc.

If not, the other course of action is to attempt to clear out, or replace the DPF, the latter obviously being a headache you want to avoid if at all possible.

Some people have reported great results with simply removing the DPF and attacking it with a powerwasher, blasting the embedded soot particles out (whilst obviously being careful not to be *too* rough and risking damaging the delicate honeycomb inside.
Others have soaked it in chemicals overnight (be careful about this as some substances could damage the coating of the special metals inside), before hosing out.

Some companies offer DPF cleaning services which involve spraying aerosols or chemicals down the inlet, which results in foam discharge out the exhaust and reams of smoke. Whether this achieves any meaningful cleaning of the DPF in real terms is a matter of intense debate, but some people have reported positive results.

Personally, I don't think there's any substitute for getting it off the car and cleaned out with pressure, but one of these products may well sort out your issue.

I can't remember exactly where, but somewhere in the Lexia / PP2000 menus where you can instigate regeneration, there's a reading which shows how full the computer believes the DPF is and how likely a forced regenration is to have a positive effect on the problem. I believe when I started getting the 'Risk of particle filter clogging' warnings, mine was sitting at 60-70% full and the possibility of regeneration helping was described as 'Not favourable' in the menu. Hopefully yours isn't that bad, at 53,000 miles I'd like to think it isn't.

If you have a search for 'DIY DPF cleaning', you'll find a lot of information, including some useful Youtube videos.

Ciaran