Renault Trafic part ID help

[Cardlawyer]

Hi, total newbie. My son bought a Trafic diesel (yes I know now lol)
2 months in it's lost it's oomph up hills and doesn't like it's accelerator being pushed.
Trying everything before going down the injector route, it seems as though they may have already been replaced as several things were not as they should be.
Can anyone please tell me if there is a pipe missing off the past in the attached photo? Following the pipe around, it stops here and not sure if something has fell or been left off.
I've attached a photo of close up and a shot of further back so hopefully someone knows what I'm talking about!
Thank you!

[Cardlawyer]

[Ritchie230]

It's hard to make out what pipe it might be from the pictures but is there any fault codes stored? I have tackled similar issues on Renault traffics and Vauxhall vivaros with the culprit being blocked vacume pipes but if the pipe was a missing vacume pipe you would have an engine management light and stored fault codes.