x7 failing emissions

[Agour]

My 2009 x7 failed the MOT on emissions today..

Diagbox shows P1471 — EGR valve, logged as Local, Intermittent, with the fault characterized as an open circuit.

I've attached photos from the live readings (engine on).

Seems to work fine for 30 seconds or so - but then the "no EGR" kicks in.

I assume the EGR is knackered, and this is causing the emissions issues?

Would anyone be able to tell me the exact part number for my vehicle too please?

(or point me in the direction of where I can find it..)

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

Thanks!

[RichardW]

Does it have a DPF?

[Agour]

Does it have a DPF?

yep! I filled up the Eolys 6 months ago or so.

All readings for DPF seem ok on diagbox? (photos attached)

Car read about 2.5 on the emissions test, and he said the limit was 1.5

[Agour]

I also wondered if it could be the injectors...

I do also get p1351 error.. but as far as I can tell, this is unrelated and you can pretty much ignore it.

It has done about 120k miles, so may be due a dpf clean? From what I understand, the dpf should catch all the black soot?

[RichardW]

If it's got a DPF and the reading is 2.5, then the DPF is broken unfortunately. Check the tail pipe - is it sooty?

[Agour]

If it's got a DPF and the reading is 2.5, then the DPF is broken unfortunately. Check the tail pipe - is it sooty?

Yeah, very sooty! It left a big patch of soot on the floor of the MOT station...

Do you know what the access is like to get to it?

Thanks for the help, I appreciate it

[RichardW]

Not sure on access, is it the 2.0 16V unit? Pretty sure it will be under the car.

[Agour]

Not sure on access, is it the 2.0 16V unit? Pretty sure it will be under the car.

yeah I think so!

I've ordered a replacement, so will swap it in.. hopefully that sorts it.

Think its worth swapping the EGR valve out too, given the error codes?

[RichardW]

If it's not putting the light on, I wouldn't worry about it for now. Get it through the test, clear the code, and then see if it comes back.

[Agour]

If it's not putting the light on, I wouldn't worry about it for now. Get it through the test, clear the code, and then see if it comes back.

Gotcha, thanks! I'll swap the dpf over and see what happens

[Agour]

I was just redlining my car in second gear, and got "anti pollution fault" with engine management light.

¯p0088 and p1166.

P1671 also came up, but I suspect that's just a red herring.

Rail pressure got up to 1843, and from what I understand if shouldn't go over 1500?

Could the fuel pressure regulator be the cause of the emissions woes?

[RichardW]

A DPF is a sieve - it catches soot particles, and it should catch >99% of them. If there is appreciable soot at the tailpipe it is broken up and will have to be replaced.

Other things may influence how often the car has to regenerate it, and indeed whether it will at all - but until you have the DPF working as intended you won't know that. If there is other colour smoke (blue or white /grey) then the engine has other problems which the DPF won't catch and will need a separate fix.