DIY DPF cleaner

[21TonyK]

Are these sprays snake oil? Worth a bash? Can do no harm?(!!)

Cars done 90K and until about 10k ago probably very little other than local stuff. Getting a pressure code and won’t rev above 4300

[E-bmw]

Better to have it removed & cleaned properly, at which time the pressure sensor pipes can be cleaned.

Just adding something into the fuel will do virtually nothing.

[21TonyK]

E-bmw said:

Better to have it removed & cleaned properly, at which time the pressure sensor pipes can be cleaned.

Just adding something into the fuel will do virtually nothing.

That was the garages advice but with the caveat I should get it through its MOT and move it on which is the plan.

It’s a B37 diesel mini and warned it’s a major job hence wondering if it might help. No EML or smoke.

The spray I was looking at goes in the O2 sensor hole. Not a fuel additive.

[GreenV8S]

I've seen professionals clean DPFs using a foaming solution and the right diagnostic tools to get the electronics to cooperate. It doesn't look particular complicated or expensive to have done professionally, but I can see plenty of ways for an ignorant DIYer to get it wrong.

[stevemcs]

More likely a blocked pipe in the same way it does on the Nissan engine.

There is a sensor and pipe that runs to the manifold - sits under the turbo at the back

https://youtu.be/d3T_83pByts?si=SXTz-p8lPMQ9AKEx

[21TonyK]

stevemcs said:

More likely a blocked pipe in the same way it does on the Nissan engine.

There is a sensor and pipe that runs to the manifold - sits under the turbo at the back

https://youtu.be/d3T_83pByts?si=SXTz-p8lPMQ9AKEx

That's interesting!

Will have have a look later in the week when I have a couple of days.

In the meantime still battling a MAF error!

[stevemcs]

Maf errors are rarely that, there is a plastic breather pipe that cracks on these, lift up the engine cover, left hand side

https://youtu.be/87unAJsUcIU?si=YKyVfgXzCKEwNqEq

Usually linked to the pressure code.

[21TonyK]

stevemcs said:

Maf errors are rarely that, there is a plastic breather pipe that cracks on these, lift up the engine cover, left hand side

https://youtu.be/87unAJsUcIU?si=YKyVfgXzCKEwNqEq

Usually linked to the pressure code.

Replaced that once already but worth checking (that and all the others)

Now getting more codes

[E-bmw]

As above MAF errors are rarely MAF problems, just that the MAF is what is finding the issue.

Check everything in the inlet path for tightness/leaks.

[Jakg]

I've used it (Mannol DPF spray via the pressure sensor) in conjunction with a manual regen and found it helped, but obviously it's not as good as an off-car clean.

Bear in mind that sometimes the problem can be upstream - e.g. on some BMW diesels, it won't regen if there's an engine fault code, or if the engine isn't warming up properly. So cleaning the DPF is pointless until the root cause is addressed.

[thebraketester]

What is the maf error that is showing?

[21TonyK]

I’m getting.

P0101 [0x0101]
Mass air flow (MAF) sensor/volume air flow (VAF) sensor - range/performance problem
Mass or Volume Air Flow Circuit Range/Performance
Status: Confirmed

---

P00BC [0x00BC]
Mass air flow (MAF) sensor A - circuit range/performance
Status: Pending

---

24CF00 [0x24CF00]
Status: Pending, Confirmed, Test failed since last DTC clear, Test not completed during this operation

[PushedDover]

we tried the cans on a RAV4 a few years back, not much gain -
Found a 'DPF Doctor', industrial estate local operator that just did it properly and efficiently for c.£100 I recall.

https://the-dpf-doctor.com/