Hi I have engine system fault message, car running normally but error codes indicating problem with eolys additive tank i.e. dpf not activeky regenerating. Contemplating a very long motorway journey circa 5000km, will the filter passively regenerate sufficiently for me to do it? Best Regards.

They're meant to, but they just don't get hot enough even if you cruise at 90mph.  

If you haven't got any Eolys additive, it won't be able to regen anyway.  It's crucial for this type of DPF unfortunately.  Is it possible the tank is just empty?  Or is the error code indicating an actual fault with it?

Hi Tomsfocus thanks very much for the reply.  Unfortunately the tank is 3/4 full (very strange after 115000km as I am not aware of the tank being replenished), so it is just not working.  Am I correct in thinking that the eolys is supposed to be added when the diesel fuel tank is filled up? In which case, can I buy a fuel dpf additive and add that to achieve the same effect?  Best Regards.

1 hour ago, Steve Portugal said:

Hi Tomsfocus thanks very much for the reply.  Unfortunately the tank is 3/4 full (very strange after 115000km as I am not aware of the tank being replenished), so it is just not working.  Am I correct in thinking that the eolys is supposed to be added when the diesel fuel tank is filled up? In which case, can I buy a fuel dpf additive and add that to achieve the same effect?  Best Regards.

Have you physically checked the tank level?  It must have been broken for a while if it's only used such a small amount. 

Yes, the additive is injected into the fuel tank after filling up.  You could add a little Eolys to the tank yourself each time.  A shop bought fuel additive won't give the same effect unfortunately.  

However, I suspect the PCM won't allow a DPF regen if it thinks there's a problem with the Eolys tank/injector so that will need to be fixed really.

Thanks again,TomSFocus very useful information!