c5 2.2hdi inlet throttle butterfly question

[rfhspares]

Hi, my 2004 c8 2.2hdi has got ridiculously low power lately, ticks over smooth but I put my foot down and I can hear the turbo whistle up and the hose from the intercooler goes solid but I have next to no power. Getting up hills is a massive struggle. Car revs to 5000rpm and the EML doesn't come on but I know it does work. Checked map and maf sensor with scan tool and readings are accurate. p1435 additive system is the only fault code I can find.
I am wondering if one or both flaps in my throttle body are not opening and allowing air flow to my engine and I just read that you have basically forced your butterfly flaps to stay open permanently and you bypassed the vacuum bleed solenoid valves, did I understand that correctly? wouldn't this create a lean mixture with no control over air flow?

[ekjdm14]

I just read that you have basically forced your butterfly flaps to stay open permanently and you bypassed the vacuum bleed solenoid valves, did I understand that correctly? wouldn't this create a lean mixture with no control over air flow?

Diesel engines don't require control of inlet air, the revs of the engine are controlled pretty much entirely by how much fuel is added to the air. (in other words a lean mixture doesn't cause overheating issues like it would a petrol).

I know you've checked the maf readings but have you also tried a run with it disconnected electrically? if the maf is indeed healthy then you'll find even less power & bad driveability but if it's duff then little will change with it disconnected. Having said that, what other live data have you checked? I'd want to be looking at boost pressure, DPF differential pressure, fuel pressure etc plus make sure the EGR is operating correctly (not just electronically, but physically in that they can stick slightly open with age)

[rfhspares]

Thanks for your reply. If I disconnect the maf the car has even less power and goes in to limp mode and won't rev above 3000rpm. I took a video of what I scanned on the live data. I didn't scan the dpf data, I do have a warning about the additive system and additive levels, when the additive was topped up some years ago we couldn't get the additive level to reset, the scanner did all the resets that should have reset the values but they just wouldn't work. Tried a few garages with different scanners but no joy and didn't want to pay Citroën prices. I know the dpf isn't blocked because it had 5 holes drilled through it when we realised it might block because of the additive problem. I will check the dpf pressures with the scanner though just to double check.
Am wondering if the egr is slightly open, planning on blocking that off to check.
Here's a few screen shots attached.