Citroen Dispatch injector/EGR issues

[Charmander21]

Hi All,

I have recently acquired a 2020 Citroen Dispatch with the 2.0 Blue HDI DW10f engine, 1250000 miles. VF7**************[VIN obfuscated, can be read by forum staff] I've had it for about a month and there are a couple of outstanding issues I'd like to get sorted. I've had a consistent P1164:22 code 'fuel high pressure sensor signal - value above setting', which eventually called the engine light. From what I understand, this code specifically refers to fuel pressure on startup. Due to that engine light, and also experiencing rough idle and quite a bit of white smoke from the exhaust on startup + 15-20 minutes into driving, I took the van to my local garage.

They confirmed the rough idle and smoking, and found some metal particles in the fuel filter. They proceeded to do a clean of the engine fueling system (not the tank), and checked the high pressure fuel rail sensor.They wiped the error codes but suggested that further diagnostics were necessary as the idle continued to be rough and smoking. I've not noticed symptoms of a HPFP failure, so I'm assuming these particles came from the tank or elsewhere in the system.

I then took the van to a specialist garage (who were unfortunately very busy and not able to do a full diagnosis at this stage) where they suggested that the smoking issues could be cause by a stuck EGR valve. According to diagnostics that I've done myself, there does seem to be an issue with the EGR valve being more open than it should be.

Since the clean of the fueling system I've driven the van over 300 motorway miles, as well as some low gear high revs driving to try and work the engine a bit, as suggested by the garage. I've not noticed smoking lately, apart from cold starts. And the P1164:22 code hasn't returned.

I've done some live diagnostic logging of the cylinder correction at idle and consistently get the following: (deviation from 1.0)
CYL1 -1.5%
CYL2 -9.3%
CYL3 +4.4
CYL4 +5.8%
In actual driving conditions, these converge to 1.0

I've also done quite a bit of live logging on the EGR actual consistently exceeds the commanded position:

Condition	Commanded	Actual	Gap
Idle / stationary	62.9%	99.2%	+36.3pts
Low-speed town	60.0%	98.4%	+38.5pts
Town / urban cruising	53.6%	90.0%	+36.4pts
A-road / dual carriageway	54.0%	88.3%	+34.3pts
Motorway cruising	23.9%	43.7%	+19.8pts

What I'm hoping for some advice on - firstly, do the cylinder correction figures warrant further diagnosis of the injection system? (bearing in mind I'm no longer getting any error codes related to this - the only fault code I'm still getting is a U2FFF:00 and I've not been able to get any info on this) both garages were wary of doing a leak-off test as they said it's very easy to damage the connection points. and secondly, does the EGR data suggest that it's worth replacing the EGR? (I've had a quote of 514 to do this) I'm assuming that in it's current state it will just cause further problems down the line. Thanks in advance for any advice.

[Huskyxantia]

Run your post via Ai and here's the results

Here is a breakdown of what your live data and diagnostic findings actually indicate for your 2.0 BlueHDi (DW10F).
​1. The EGR Valve Issue
​Your live data for the EGR valve is the most definitive finding here.
​The Problem: The EGR actual position consistently exceeds commanded position by 20% to 38%, staying nearly wide open (90%+ at low speeds/idle).
​Why it causes your symptoms: Excessively recycled exhaust gas starves the engine of fresh air (oxygen), leading to incomplete combustion—especially on cold starts. This directly causes rough idling and raw, unburnt fuel smoke (white/grey smoke).
​Verdict: Your EGR valve is heavily carbon-fouled or mechanically sticking open. Replacing (or thoroughly cleaning) the EGR valve is necessary. Leaving it stuck open will heavily soot up your DPF (Diesel Particulate Filter), cause intake manifold buildup, and cause persistent cold-start smoking. A quote of £514 for parts and labor on a DW10F is reasonable given the labor involved in reaching and replacing the unit on the Dispatch bulkhead.
​2. Cylinder Smoothness / Injector Correction
​Your cylinder balance figures (smoothness corrections) tell an interesting story:
​CYL 1: -1.5%
​CYL 2: -9.3% (ECU is pulling back fuel, indicating this cylinder is over-performing or the injector is over-fueling/leaking)
​CYL 3: +4.4%
​CYL 4: +5.8% (ECU is adding fuel to compensate for a slightly weaker stroke)
​Assessment: The fact that these values converge near 1.0 (0%) during actual driving is key.
​At idle, a sticking-open EGR valve severely alters air distribution across the intake runner, which frequently causes artificial smooth-running corrections at idle because cylinders receive uneven air flow.
​Recommendation: Do not pull injectors or perform invasive fuel system tear-downs just yet. Sort out the EGR valve first, clear adaptive learning values, and then re-check the live injector correction at cold and warm idle. If Cylinder 2 remains heavily in the negative, an injector leak-off test or bench test can be revisited then.
​3. Fuel High Pressure & Metal Swarf
​P1164:22: Indicates the rail pressure sensor saw a signal above expected threshold during start/crank sequence. Since it hasn't returned after 300+ miles of driving, it was likely transient (possibly triggered by air/pressure fluctuations during initial system checks or pressure regulator lag).
​Metal particles in filter: This is the element to keep an eye on long-term. Bosch/Delphi high-pressure pumps (HPFP) can shed micro-fine metallic debris when failing, which migrates to the fuel filter. Since the first garage cleaned the housing and replaced/cleaned the filter, inspect the fuel filter element again in 1,000–2,000 miles. If fine metal debris reappears, HPFP replacement and full system flush will be required before total pump breakdown ruins the injectors.
​4. Fault Code U2FFF:00
​Meaning: U prefix codes are network/communication errors (BSI/Multiplex network). U2FFF is a generic manufacturer-specific communication glitch code frequently stored in Peugeot/Citroën BSI (Built-in Systems Interface) modules when non-critical diagnostic polling fails or battery voltage drops slightly during cranking.
​Impact: It is non-critical and unrelated to your engine smoking or idle issues. You can safely ignore it.
​Recommended Action Plan
​Address the EGR Valve: Proceed with replacing or cleaning the EGR unit.
​Reset Adaptations: Ensure the garage performs an EGR adaptation/learning reset via diagnostic tool (DiagBox / ECU reset) after replacement.
​Re-evaluate Injector Data: Log idle cylinder correction values again on a cold start after the EGR replacement to see if Cylinder 2 settles down.
​Monitor Fuel Filter: Check the fuel filter bowl at your next service interval for fresh metal filings.

[Charmander21]

Thanks, looks like getting the EGR replaced is a good idea. Unfortunately that quote to replace was a mistake and it's quite a bit more. 1200 at main dealer, 750 at an independent. Out of interest what AI are you using, is it automotive specific?

[Huskyxantia]

Only Gemini, its been pretty good with stuff ive been doing on my cars, I like to use it to log all the service stuff and so on , it will even ask how the car is performing, over look your diagnostic session, share the screen put camera on show it the screen then it will tell you every, even if you so ok smart ass let's have that in simple terms , it will do it .. It can even help with various car part searches and prices too , its not always 100% but so far its been pretty handy for what ive been doing