Citroen c5 2.2 hdi 150KW power loss

[Amatercina32]

Hello,
I have the following problem with my Citroen C5 2.2 HDi (150 kW).
When the car idles for a longer period (15–20 minutes), it loses power once I start driving.
There are two scenarios:

The car cannot exceed 3000 RPM (even in N or P) and it gains speed and revs very slowly.

It accepts revs, but the acceleration is extremely slow.

It is worth noting that there are no error codes except for U1217 and U1213 from the mechanic's diagnostics.
So far, I have installed a new battery and replaced the fuel pressure regulator. There is no difference, except that the car idles better now.

[mickthemaverick]

Since your trouble seems to be after prolonged idling I'd suggest you may have a sticky EGR valve which may respond to a relatively cheap cleaning using one of the proprietary EGR cleaners on the market. Worth a try I would think!

[Amatercina32]

Thanks for the reply. I'm not sure if this is actually an issue.
because according to the diagnostics, the 'EGR Desired Position' and 'EGR Actual Position' are identical.
Also, the EGR closes (drops to 0%) as soon as I rev the engine/apply throttle.
I'll clean the EGR regardless; it definitely can't hurt.