Particulate Emission Filter - Max no of regens reached!?

When excess soot is trapped in the particulate filter the engine management unit starts the regeneration cycle. This involves raising the exhaust gas temperature to burn off the accumulated particulates. There are 2 main components in accomplishing this task. The first is a special chemical that is held is a tank under the car, it's electrically dosed and added to the diesel. The second part to this is the engine management unit will start to post inject diesel into the combustion chamber just as the exhaust valve opens, further increasing exhaust temperature. There is a cost to these smoke free HDi engines, slightly higher fuel consumption (and CO2) but their particulate emissions are very low, probably better then many petrol engines.

The problem is that this regeneration procedure requires load on the engine, typically, you must be driving at a constant speed of say 40mph for a few minutes for it to occur and complete the procedure.

If your daily driving cycle does not include a section of moderate speed driving, plus you've got glow plug / pre heating problems the smoke produced may clog the filter quicker then it can burn it off.

It would make more sense if the PEF fault was caused by the pre heating failure.

Probably not, but what is a typical journey for this car, a 2-4 miles trip across town, or 20 miles on A-road / Mway?

My mechanic has said Peugot have contacted them and decreed a filter change should be done every 50K, because regeneration is just not effective enough. A recon filter is about £200 so expect a £300 bill. I have done 65000 and my 'clean filter' light is pereodically flashing. Regards phil.