I've just used DIS to run a back pressure test on my 2004 E61 with approx 110k on the clock. The values I got back were:

@Idle - 15.9 mbar (Max permissible 65 mbar)
@2000 RPM - 33.9 mbar (Max permissible 150 mbar)
@cut-off speed - 144.9 mbar (Max permissible 250 mbar)

Can anyone tell me what these values reveal about the state of health of the DPF?

Thanks.

 

The values look pretty good (i.e. the DPF is fine) however the values get progressively worse until the car regens.

If you can keep the values around there when the car demands a new DPF at 120k miles you can safely ignore the mileage based warning.

 

Thanks JasonH.

It's been a while since it has had a regen, but I'm going on a long trip tomorrow so it should regen. I'll run another test after that to see if there's any difference. Good to know I won't have to deal with the DPF for a while!

TM