dpf filter has two air pressure sensors one in front of filter one at rear, these tell the ecu how blocked with soot the filter is and at a point around 80% it will tell ecu to regen the filter, it does this by changing ignition points via the injectors and runs engine rich with fuel to generate heat within the exhaust system and turbo and engine,, driving the car at 3000 revs for more than 20 miles on a motorway once a week is good to keep clear, all of the above is fine when the filter is under 75000 miles old, the problems start after this mileage as the filters are designed with 75000 as a service replacement item, the additive tank they also run needs replacing every 45k or filter will block, also bare in mind turbo's are designed to last 80-120k based on engines with unblocked dpf filters, when filters block they will soon take out the turbo, 100k car with factory filter blocked is just waiting to destroy your engine as when turbo fails those engines go in to diesel runaway, ie cant not stop them from eating own oil and reving to red line until it breaks, below link is a dpf element by far cheapest option on the psa 1.6 hdi engines, also a link for the best dpf and injection cleaner i have found its call cataclean dpf,, but nothing will clear a 75k plus filter as its the residue produced from regens that black them and will not burn a wayThanks a lot knt! I'll wait for mike's answer then!
Yes, I've seen this additive before in a Tesco's, it seems to be more popular than Wynn's, but I'll go to Halfords today to have a look at a greater range and ask for their help in choosing the one.
By the way, I came across this app & OBD2 package from Carly (www[dot]mycarly[dot]com/en/app/bmw/), and it has the ability to monitor the DPF (how many grams of soot there is in there), see that live as you're driving and even perform a force regeneration (although it just points to the ECU to do that when all conditions of temperature and mileage are met). I think that would ease my mind a little bit to monitor when it starts to become clogged (but before the light comes on) so that I can take it for a good ride on the motorway!