C8 2.2HDi really hates hills - turbo or DPF issue perhaps?

[MattBLancs]

If the MAF is unplugged the ECU goes into default mode. As you have discovered a quick and easy test to see if the MAF is functioning correctly.

If you can access it you may be able to clean it. I used carburettor cleaner but ther is now a dedicated MAF cleaner (same thing I suspect).

Mine was ailing as the wheel arch liner had exploded and exposed the air + water, grit and leaves intake and made a mess of the MAF and filled the air filter with water and roadside crap.

A couple of squirts and it was OK. Don't touch the wires with anything other than the spray and don't drop or shock the MAF, they are exceptionally fragile.

Is that not after the air filter? I'm amazed how much muck on the gauze there!

[MattBLancs]

P.S. not sure if MAF unplugged severe enough impact on emissions to affect that testing, but think will bring engine management light on, and that's the MOT issue isn't it?

[tearing hair out]

For diesels, "You need to inspect MIL fitted to diesel vehicles including hybrids with 4 or more wheels and first used on or after 1 July 2008.". Mine is 2004, so I believe I am ok. (2003 for petrols)

Which doesn't mean it won't fail on something else.

[tearing hair out]

I'm not sure I want them to rev it to the red line with the sensor disconnected though...

[Rp0thejester]

Engine light on anything before 2008 I think is okay, Marc answered it in my MOT Questions topic.

[Rp0thejester]

I've also just unplugged my MAF sensor. What a car and what an engine!!! It wasn't that powerful when got her 10 years ago!! I've fallen in love with her again.

is it just dirty or replacement needed?

[Hell Razor5543]

Engine light on anything before 2008 I think is okay, Marc answered it in my MOT Questions topic.

However, if you take the car in for MoT after 20:08 with the engine light on you might have a problem!

[myglaren]

Is that not after the air filter? I'm amazed how much muck on the gauze there!

It is. As said the wheel arch liner disappearin a cloud of plastic shards and the intake is low down in the wheel arch and consequently sucks up lots of water and other debris. The filter was ruined and the strange 'horn' thing was full of water and grit. Naturally the intake is on the left of the car, ideally placed to ingest all the crap from the side of the road.
It did clean up well and was no further trouble. I did fit a new wheel arch liner of course.

Cleaned the MAF on the other C5 too with equally pleasing results.

[Rp0thejester]

The air intake has to be in worse place possible, I'm even thinking of fitting an air induction filter to keep it from sucking up the road crap through its elephant trunk intake

[Rp0thejester]

The prongs on the right hand side, are they supposed to be that close to the metal plate? Mine are miles away.

[myglaren]

Couldn't say. IIRC this was in fact a replacement MAF, A Siemens/VDO bought from the local Citroen dealer.
It could be that the thermistor would be better placed more in the airflow.

[tearing hair out]

The prongs on the right hand side, are they supposed to be that close to the metal plate? Mine are miles away.

I suspect as long as they are far enough from the support that it doesn't interfere with the airflow over the wires, it doesn't really matter how close they are (and presumably they are calibrated anyway).
https://www.delphiautoparts.com/en-gb/r ... it%20works

EDIT: Oh, you mean the thermistor - what @myglaren said. I should learn to read things more carefully.

[Huskyxantia]

Looks like its time for a new maf. Plus a thinner wallet after

[Rp0thejester]

Hmmm, Citroen can get stuffed, my pounds are staying in my wallet, eBay to the rescue!! If I can get the part number of Marc

[Rp0thejester]

£25, Captain eBay to the rescue!