Eat8 1.5hdi stuttering and then stalled at traffic lights

[Sol]

I wonder if this is a self-induced judder, to alert (force) you to go to the garage when the Adblue system isn't working properly, in case you were likely to just ignore it and drive...

[boop]

No, Adblue diagnostic messages have been proper so far. Call for service being the most apparent symptom.

[Elgreco]

How wonderful. One of our Berlingos started to do the same exact thing. It's now at the dealer. I'll keep you posted.

I don't believe it....
While I am writing , once again, I would like to warn people about something else that came about through this story.
When the car first had problems it was xmas eve so a mechanic who was friend of a friend came out and did the diagnostics and told me to be careful because when a car shows multiple faults like mine , the dealers tend to just change parts and see whether it is the cause... while charging of course.
The last guy who fixed it by disconnecting the Adblue is 100% sure that the Maf Sensor that citroen charged me for had absolutely nothing to do with it.
Does anyone here know? Are diagnostics so vague that this can be true?? 
On the other hand they are shooting themselves in  the foot as the second time they wanted another €400 I said no thanks.

[boop]

Mine's under warranty, luckily, so whatever they do it's on them.

[Sol]

How wonderful. One of our Berlingos started to do the same exact thing. It's now at the dealer. I'll keep you posted.

I don't believe it....
While I am writing , once again, I would like to warn people about something else that came about through this story.
When the car first had problems it was xmas eve so a mechanic who was friend of a friend came out and did the diagnostics and told me to be careful because when a car shows multiple faults like mine , the dealers tend to just change parts and see whether it is the cause... while charging of course.
The last guy who fixed it by disconnecting the Adblue is 100% sure that the Maf Sensor that citroen charged me for had absolutely nothing to do with it.
Does anyone here know? Are diagnostics so vague that this can be true?? 
On the other hand they are shooting themselves in  the foot as the second time they wanted another €400 I said no thanks.

Normally, the first thing we would check for stuttering and stalling at junctions, is the MAF. But the airflow readings from it can be measured by diagnostics. The values for idle and full RPM are documented. It is entirely possible to tell for sure, whether it is bad, or not, for an equipped garage.

[Elgreco]

I m about to have a nervous breakdown.... the Adblue is not causing the stuttering.
Again nothing showing on the dash. The only thing I have noticed is very high fuel consumption , hovering over 8.5ltr/100kms compared to the usual 6ltrs...

[Sol]

I m about to have a nervous breakdown.... the Adblue is not causing the stuttering.
Again nothing showing on the dash. The only thing I have noticed is very high fuel consumption , hovering over 8.5ltr/100kms compared to the usual 6ltrs...

So the stuttering is back? That with high fuel consumption would indeed sound very like a MAF sensor issue. Do you know any reliable person with a diagnostic kit and the data to determine whether your airflow readings at idle and full throttle, are correct? You could disconnect the MAF and it would drive normally when that sensor was faulty.

Next it could simply be drawing air into the engine which was not measured by the MAF , for example from a split  in a plastic pipe on the intake, or a loose intake tract / tube. But that would mean it ran lean, so reduced fueling.

Last thing is the CAT o2 sensors, on a petrol they can cause over-fueling if there is an exhaust leak at a joint, allowing air into the flow, so measuring more oxygen than is actually remaining in the gases, that causes over-fueling too. Not sure about the amount of attention a diesel pays to the O2 sensors. Petrol's use it in closed loop for fuel / emission control

[Elgreco]

A massive thank you. Yes it's back , the stuttering.
May I ask, would you exclude transmission problems?
I have to wait till Saturday now. Noone available till then.
Keep you posted.

[Sol]

hmmm on the auto (piloted manual) box, perhaps it is possible. May be a jerky auto clutch or something, but that would require Citroen to properly diagnose, or a very good independent PSA garage.

I'd stay away from the garage who said it was the Adblue. That's like saying your computer mouse mat has a virus.

Does the engine stutter in Neutral, when idling or when the throttle is held to say, 2500 rpm? Is the engine steady is where I am going. If only stuttering when driving in gear, then it could be the gear box or MAF.

But here is a thought, there is a thing called brake / throttle coherence. If you are on the throttle, driving, and you touch the brake pedal lightly with your other foot, the ECU will cut the throttle off, so it is possible your brake switches are "stuttering" the brake lights on and off, which would cause the ECU to record "brake / throttle coherence error" or similar, and jerky driving response. Get someone to look and see if your brake lights are flickering when this jerkiness happens (a friend driving behind)

Ask me how I know this... (just happened to me)

[boop]

Update: throttle body and new EGR piping ordered, possibly something else. Engine drop for parts replacement next week.