differential pressures for what part of the car exactly. Regards Peter

Indeed it is the DPF differential pressures, how did you guess?

If you are referring to the cleaning techniques that involve washing out with power hose, yes I have seen them, but I don't really know how effective they are. Also, if the DPF has been cleaned, doesn't the PCM / ECU have to be reprogrammed / reset, as it will still be working based on the values / readings of the DPF as it is at the moment, before being cleaned? I've also heard it can be a bit risky cleaning with water as it can make the ash in the DPF set like concrete.

Thing is I can monitor the differential pressures of my DPF, I just don't know what sort of values I'm looking for them to be good readings.

I use Forscan which measures 'differential pressure on particulate filter' (DP_DPF) in kPa. To measure a regen I use a combination of EGT sensor readings (PPFT) and 'distance since last regeneration trial' (DIST_REGEN) which resets itself to 0.0km once a regen has been acheived. I did some live data scanning yesterday and was able to establish that the car is performing regens as should be.

I've heard that kPa readings for DP_DPF of <10kPa are normal readings, however the lower the better, however I've also seen info that says that <30kPa readings are considered normal. This has now left me confused as to what sort of readings I should be getting for a good DPF and bad one. From the live data scan yesterday I was able to see that at 1600rpm in 5th gear the DP_DPF reading was 2.5kPa, and when accelerating to 2350rpm in 5th gear the reading levelled off at 7.0kPa.

Not sure if any of this info is of use to any of you. Any views would be greatly appreciated.