Mk6 2.3 Petrol Engine Codes P0401 and P0171

[neroblack]

Hello All,
After trawling through all the posts I couldn't find a symptom that aligned with my own. This could just be another replace EGR post but lets see.

Van Specs: Mk6 2.3 Petrol RWD MWB Mid Height.

Back story: Bought the van off a couple about a month ago who just had the EGR replaced. This was diagnosed by their mechanic and apparently from what they said there were some issues at the mechanic with installing the new one and thinking that it didn't fix whatever issues the van had. I have no other reference to what, if any engine codes where thrown to diagnose EGR etc. just that the mechanic replaced it. When I bought the van it ran fine except for a very occasional idle issue which would sometimes result in cut out/stall at idle. I changed oil, oil filter, air filter, plugs, serpentine belt, coolant, thermostat just as a general service when I got the van.

Symptoms today : After about 3000km running after buying vehicle, engine light just came on after starting up. Van runs fine through acceleration etc. just that little pre-existing intermittent idle issue. Engine codes being thrown are P0171 System too lean (bank 1) and P0401 Exhaust gas reticulation (EGR) system insufficient flow detected.

Question: Have people had experience with purchasing poor aftermarket EGR valves? Could there be another issues causing these EGR symptoms? Ive read about DPFE sensors paying a role in this? Spoke to local mechanic and he said if they already replaced EGR then replacing again would be wasting money and start looking elsewhere. However I know even new parts can arrive with issues. Any way to check EGR operation or anything else?

Side note: The temp gauge was also not working, so after replacing the temp sensor without avail I checked the thermostat and someone had cut out the entire spring mechanism, effectively removing the thermostat all together. Replaced thermostat and temp gauge works fine.

Lastly engine makes a tinny noise above say 2800RPM during acceleration however no loss of power.

Any help would be great please!

[madmart132]

Has the van got lpg fitted ?
I get those codes all the time , I believe my vans have airleaks somewhere in the intake system but generally I don't get them when running on petrol no idea why .

[neroblack]

Hey Madmart,
Nope it doesnt run LPG, would you recommend checking for airleaks around the inktake side?

[madmart132]

If the van runs ok just leave it alone .

[twin--turbo]

our 2.3 galaxy quits at idle occasionally. I suspect it's air leak related myself. It's done it for years...

Unless it's causing major issues your probably best leaving it alone as stated above.

[neroblack]

Thanks guys,
whilst true the van runs 'fine' for the most part, and the intermittent idle isn't a major concern, what is a concern is that this minor issue causes the CEL to come on, and stay on. This has the potential to mask and other major issues that might occur in which the CEL would then come on and make me aware of when they happen. If the light stays on, how will i know if another issue occurs???

[neroblack]

UPDATE.
P0401 Exhaust gas reticulation (EGR) system insufficient flow detected was fixed by replacing the DFPE sensor.

Put a smoke machine onto the air inlet, air leak coming out of the IAC Valve on top of the intake manifold behind the throttle body. Replaced IAC and P0171 System too lean fixed.

Hope this helps others.

Unfortunately now having jumping and stuttering issues whilst driving, time to hit the forums again to try and sort out problem. Replaced fuel filter, drained and cleaned out fuel tank, fuel pressure test comes back fine....

**sigh**