Change DPF yourself

[pc4]

Hello everyone,
Our car (2014 C4GP mk2 1.6HDi 184000km) advanced from wanting eolys to saying the the DPF needs changing. I've been searching here and on the net in general and I think I know the answers to my questions but I need to think out loud and see if I'm on the right track.

Background. After last refueling the car came up with the "particle additive low" warning and a few days later "Engine fault warning". Took car to independent garage that serviced it and refilled the eolys but they got cam-bus errors their diagnostic tools couldn't interpret. Took car to Citroen dealer who says car is showing P1445 "Too much additive added, change DPF" and was quoted back of hand price of €2500. We don't really need a diesel anymore so trading it in for something that runs on petrol is tempting but I'm unsure if a dealer would take a trade-in that requires costly service before resale or if they do I'll get very little for it. I'm also hesitant to fork out the money needed to fix it but... The cam-belt was changed last year and the brakes are new for this year so I think the car is in pretty good shape, or just at the brink of becoming a money pit...

Questions:
1 - Is it reasonable for the DPF to give out now? When I spoke to the independent garage they thought it could be something else but I'm leaning towards trusting the ECU on this.
2 - Can you change the DPF yourself? I've only found one video of someone doing it on a C4 mk1
(
and while fidgety it didn't look impossible, provided it is the same procedure for the mk2. I will of course need to take it back to the dealership to clear the errors and mark the eolys as refilled but if I can do the change myself my estimate is that it will cost me €800 instead of €2500.
3 - I think I've found the right part but want to check against the original part. I expect any stickers to have been burned off a long time ago, so do these filters have part numbers stamped on them? My thinking is to get the filter out, check the number on it and then order a replacement.
4 - If I do change it myself what should I look out for and be extra careful with? I suspect any sensors and pressure pipes needs to be handled with care.
5 - Do I need a new filter or could a thorough cleaning, after removal, sort it out? I'm thinking that the error indicates that the eolys have saturated the filter and it really is gone but maybe DPF cleaners fixes this.

I think that is it, thank for reading and take care!

[RichardW]

Did the Cit garage manage to re-set the low additive?

On the DFP too much additive - this is a pre-programmed figure based on mileage. In all probability it is actually OK - if the differential pressure is OK (<10mbar at idle, 40mbar at 3000 rpm) - and regens are not too frequent, then you can just tell the car it has a new DPF and the warning will go away.

[shtu]

If you're moderately handy with the spanners, it's not difficult to remove if you can cope with the typical susty exhaust clamp. I would suggest you try cleaning it before replacing. I did a thread recently that talks through what I did, so won't repeat it here. It also has lots of real-world live data to compare against.

I found a pressure washer not ideal for the cleaning job, a garden hose and time worked for me.

The broad procedure is to refill tank, wash out dpf, then tell the car that the tank has been filled and dpf replaced.

[Rp0thejester]

Well members get the part numbers from their VIN, it's a tenner to be a member and ask as many part numbers you want. I don't think the DPF is stamped with a number, that went out years ago once the internet got involved. If you're worried about buying the wrong replacement DPF then I suggest the tenner for the years that you have access to part numbers etc. Eolys wouldn't saturate the DPF to stop it working, it's there to make it work better, reduces the burning temperature to keep the DPF cleaner for longer. If I'm wrong on this then I'm sure the forum will let me/us know!

[pc4]

Did the Cit garage manage to re-set the low additive?

On the DFP too much additive - this is a pre-programmed figure based on mileage. In all probability it is actually OK - if the differential pressure is OK (<10mbar at idle, 40mbar at 3000 rpm) - and regens are not too frequent, then you can just tell the car it has a new DPF and the warning will go away.

Not sure and I didn't think to ask once they mentioned "costly repair". They did however measure it, the diff pressure was 26mbar (at unknown revs) so if I understand you correctly it ought to be OK. No idea on the regen frequency.

Do you know if the "DPF risk of clogging" is tied to the diff pressure? Because we've never had that warning.

[perfidus]

As @RichardW said, the quoted error P1445 "Too much additive added, change DPF" is pre-programmed at the factory, you can find more on this on Youtube.
Basically it doesn't mean anything if the DPF diff pressure is OK and the regenerations are not frequent. It's an easy procedure for resetting this error, without changing the DPF, all it needs in advance is a good cleaning. This could be done good enough with DPF on vehicle with cleaning agent filled in via diff pressure hose, but from where I am I dont'n have any garage recommendation for you.
Of course then you can sell the car at much better value

[shtu]

What I will add is that the aerosol-can DPF cleaner I tried (sprayed in via the pressure sensor pipes and oxtgen\nox sensor fitting) made only a very marginal difference. For me, the Wynn's off-car stuff and patience worked well.

[pc4]

Thanks everyone! I've watched a few O'Rileys Autos DPF videos and between those and your answers I think I have an action plan.
1 - Get a suitable OBD2 cable (which seems to be the hardest part).
2 - Read values (pressure diff and regen count) from car and tell it the DPF is changed and eolys refilled.
3 - Depending on values given clean DPF either in place or off car and if they are really bad change it.
4 - Drive happily for years to come, possibly in another car...

[shtu]

1 - Get a suitable OBD2 cable (which seems to be the hardest part).
2 - Read values (pressure diff and regen count) from car and tell it the DPF is changed and eolys refilled.
3 - Depending on values given clean DPF either in place or off car and if they are really bad change it.
4 - Drive happily for years to come, possibly in another car...

1 - Diagbox cables are available on dba.dk, nothing on Tradera. You might have to get one shipped in from there or eBay, play around with different source countries for costs, I'd imagine another Scandi country would be best.
(top tip - I use a Virtual Machine version of the software, this is pretty straightforward to work with, easier than the painful software installation)

2 - Pressure diff will tell you if\how much it's blocked. See viewtopic.php?t=82712 for lots of numbers.

3 - If you are handy with spanners and don't mind a bit of mess, I would go for the DIY off-car cleaning. £30 for the fluid, plus time to do it. Just remove the lower section, don't mess about removing the entire thing. Take off the part these guys do



If cleaning off-car, you will see this reddish stuff coming out of the DPF



keep going until there is nothing coming out anymore. You will get to a point that you think it's done, and a little bit more will come out of yet another hole. Just keep at it, use as much water pressure as you've got, and force more through by partially blocking the dpf with your hand, block of wood, etc. If I was doing it again I would use an airline to pressurise it too, copying what the machines do.

I didn't find a pressure washer all that useful. A garden hose worked fine for me.

4 - It has made a surprising difference to how well it runs, more refined, quieter. It'a -almost- pleasant to drive now.

[pc4]

4 - It has made a surprising difference to how well it runs, more refined, quieter. It'a -almost- pleasant to drive now.

Thank you very much! I will report back once done but that might take a few weeks, I haven't been fast enough in sorting this and other things wants attention.

[pc4]

I finally pulled my thumbs out and got a cable. First leason, I could not program the ECUs without the key fob in its holder (DiagBox 9,91).

I managed to read the preasure diff, @3000rpm it is indeed 26 as reported by the dealer. Of course I forgot the regen count.

I told the engine ECU that the DPF has been changed and both the engine ECU and the Additative ECU (as per instruction from diagbox, at least I think that is what it meant with "Do not forget to carry out this operation in the multiplex additative adding pump ECU as well") that the eolys has been refilled. The errors are gone so that's good. I do however wonder if I need to prime the eolys pump? I seem to remember the car doing a sort of "poing" noise three or four times before when turning the engine off. How do I check if the pump is happy?

[shtu]

Did you acvtually touch that system? Did you add EOLYS Fluid?

If it was me and I was in doubt, I'd spend the £20ish and put a litre into the tank. As it's a "dumb" estimate of level, it won't know if it runs dry, and it sounds like you've told it that it's new\refilled.

There's a pump flow test in Diagbox that can be used to check if the pump is healty. Takes a few minutes, and puts out about 20ml of fluid.

Priming the pipes won't do any harm. It's also worth checking that the pipe isn't blocked.

If you do prime the system, be aware that the pump will tickticktick for MUCH longer than you might expect. It will also resume if you interrupt it by turning the ignition off.

[pc4]

Did you acvtually touch that system? Did you add EOLYS Fluid?

The garage where it got this years service refilled it. They could however not reset it, their diag device did apparently not show the DPF or something like that, hence the trip to an authorized dealer and another €200 spent...

I'll dig around and see if I find the pump test, diagbox is a tad hard to navigate...

[pc4]

Didn't find the test but filled up with no new errors so I think the car is happy with the coms to the pump. The "poing" noises come from the engine bay.

[shtu]

I seem to remember the car doing a sort of "poing" noise three or four times before when turning the engine off.

Sounds vaugely like an owl hooting?

EGR valve. It's normal.