DPF Restriction - Ash Accumulation

[SpunkyGlory]

Our Infiniti FX has gone into limp mode with the DPF light on the dashboard. Diagnosis suggests throws up one DTC, P242F DPF Restriction - Ash Accumulation.

Is it worth trying a DPF flush before I start deeper diagnosis, or is it likely to be an EGR fault or a fault with the DPF itself? I've no problem doing the work myself, I'm just struggling with how to diagnose the exact cause.

[stevemcs]

If its ash then its almost end of life, unless you can find someone to clean it properly. I suspect you may need to remove it from the car.

[ChocolateFrog]

Needs taking off IMO.

I've jet washed one seemed to clear it all out.

[E-bmw]

As above, needs removing & cleaning properly.

[Dooheid]

My Citroen Berlingo went into limp mode (it's the piloted gearbox, it has a manual clutch, but no pedal, it's electro hydraulic) so I got 3 gears, manually pulling the paddle, so perhaps 40mph at high rpm. Not ideal!

I removed the (long) DPF which also has the DOC (Diesel Oxidation Catalyst) and used brick acid & water (75% water 25% brick acid). I poured it in using a plastic jug in a big plastic storage box, allowed the mix to run through the DPF. I did this over and over until the water resembled a scene from the movie Jaws, very very red. That was good, the ash is red (something to do with iron oxide) so I had to do it a few more times, wash it out with water & hose, then repeat. It went from a grotty brown honeycomb to a pretty beige/grey sort of colour and I was happy.

I reinstalled the unit, reset the counter using my Autel MaxiPRO and she's back to normal, no MIL and no limp home.