Adblue fault, what else could it be?

[Arduer]

Hi

On my K9 2019 1.5 blueHDI 130, with 36200miles we started getting emissions problems. Starting at the beginning of February. In the past 2 months Citroen have replaced the Adblue injector, downstream NOx sensor, forced regen of DPD. It faulted again so they carried out a software update. Then again a week later so they replaced the Adblue tank and heated pump, carried out a second forced regeneration. Since the first fault we've only done 1272 miles and on a 70 mile trip today the Adblue countdown and engine light has started again

I'm very grateful to Citroen for having covered all the cost so far, but it hasn't half ruined my faith in the car and frayed my nerves.

What else could it be that needs fixing this time? Anyone any ideas. It's a week until my local Citroen garage can look at it.

[GiveMeABreak]

Maybe they haven't reset the Adblue counter correctly - but doing forced regenerations on the DPF is totally useless - the DPF system has zero to do with the SCR system for a start and nothing to do with the countdown message.

Apart from anything else, undertaking repeated forced regeneration is no good for the engine or components as the vehicle is not getting any cooling whilst this is taking place and puts a lot of strain on these components from the intense heat - especially the urea pipe, which is usually exposed on the underside , so won't do that much good either.