DS3 1.6D Emissions issue

[Jacko1066]

Hi everyone,

My car failed its MOT on emissions a few weeks ago.

Since then a garage has had it and they cannot seem to find the issue.

So far new air and fuel filters, oxygen sensor wiring repaired.
Have run clean BP ultimate fuel through it with an additive.

There are no fault codes, all the live data looks fine. The next port of call is to check the injectors are firing correctly, the runs an absolute dream.

Any advice would be very much appreciated?

Thanks guys

[xantia_v6]

Do you have more specific information on which emissions test failed and by how much?

[Jacko1066]

Hi, thanks for the reply.
Unfortunately it’s at the garage with the failure certificate. The mechanic said black smoke which to me eludes to unburnt fuel? There was a question whether it had been remapped, I have had it 3 years and certainly have not. Plus if it was that surly it wouldn’t have passed the previous 2 years?

[RichardW]

Post up the vin (it will auto hide) and we can see what it's got. My guess is it should be Euro 5, and shouldn't smoke at all - if it does, then likely the DPF is damaged and letting soot through.

[Jacko1066]

Will a car reg work? I am at work currently so can do that tomorrow.
It’s a 2015 plate.
The garage hasn’t mentioned a dpf tbh, it has no warning codes.
I did get a warning once about the dog but took it on a 100mile motorway jaunt and has been fine ever since.
The garage has called me this afternoon and has told me he is going to spend another hour on it tomorrow morning on the diagnostic equipment for live data, if he doesn’t get any answers then he won’t charge me. It’s quite a conundrum

[GiveMeABreak]

We'll need the VIN, sorry. Please post your VIN in full without spaces - it will be automatically masked from public view after submitting your post & will only be visible to staff.

[RichardW]

2015 will def have a DPF. Get them to check the tailpipe first - if it's sooty, then the DPF is bust.

[Jacko1066]

2015 will def have a DPF. Get them to check the tailpipe first - if it's sooty, then the DPF is bust.

Can the DPF be a bust even without any issues with the car running and no engine management warnings?

[RichardW]

Yes, as long as there is some pressure drop remaining across the DPF the computer won't pick it up.

[Jacko1066]

I have my car back from the Garage. He essentially gave up, but didn’t charge me either bless him.
Attatched is the MOT sheet.

[Jacko1066]

VIN VF7**************[VIN obfuscated, can be read by forum staff]

[RichardW]

Do the finger test, is the tailpipe sooty?

[Jacko1066]

As an update. Turns out the car was mapped and over fuelling.
The Citroen specialist charged me £800 to remove the DPF and pressure wash it, change the oil twice and apply an update from Citroen. Car passed the MoT.
Thanks everyone