I have a 2011 mk2.5 1.6tdci zetec s if that helps. 
She has a very fumey smell the odd time but after today its become nonstop and with the smell a deep growl will cone from the exhaust. The sound and the smell would come and go together but after my drive home from work today its seemingly nonstop. The yellow engine light cam on aswell and i can only assume its the dpf because i had a simmilar issue in an audi a few years back. I topped up with oil and coolant thinking that would be the fix but nada. Any idea on whats the cause. I was just going to sort out a service and all on the car and then this happens.

Yes, it's failing to complete the DPF regen.

If you read the fault codes with a Ford specific diagnostic, that should tell you why it's failing.

On a 2011 model you'll have the coated DPF, which is usually much more robust than the older Eolys additive type fitted up to 2009.

3 hours ago, TomsFocus said:

Yes, it's failing to complete the DPF regen.

If you read the fault codes with a Ford specific diagnostic, that should tell you why it's failing.

On a 2011 model you'll have the coated DPF, which is usually much more robust than the older Eolys additive type fitted up to 2009.

So would that be a mechanic job then? Would it be to risky to do myself? Thank you very much

4 minutes ago, ronantory said:

So would that be a mechanic job then? Would it be to risky to do myself? Thank you very much

Most mechanics won't have Ford specific diagnostics.  You can use Forscan to do it yourself.

never heard that name - PAT fluid is what 2016 PSA ones have

and an utter joke of a system it is...

https://www.jlmlubricants.com/en-int/blogs/additive-stories/understanding-dpf-regeneration-fluid-eolys-in-psa-engines-a-guide-for-professional-mechanics

 

56 minutes ago, Botus said:

never heard that name - PAT fluid is what 2016 PSA ones have

and an utter joke of a system it is...

https://www.jlmlubricants.com/en-int/blogs/additive-stories/understanding-dpf-regeneration-fluid-eolys-in-psa-engines-a-guide-for-professional-mechanics

 

It's the same stuff.  1.6 TDCI was a joint venture between PSA and Ford in 2004.  As such, the Mk2 Focus got the same DPF with additive requirement. 

There were constant issues with the DPF on them, so in 2009 Ford switched to a coated DPF instead.  But PSA continued with the additive type for many more years on their cars.

I'm a bit concerned - if they had a DPF how come they don't pass ULEZ ?

12 hours ago, Botus said:

I'm a bit concerned - if they had a DPF how come they don't pass ULEZ ?

DPF only catches particulates.  ULEZ is based on NOx.

Generally most either need Adblue or a NOx trap to get below the ULEZ limits.