OK, this isn't going at all well. I've just spent another hour or so looking (not even slept tonight). Wherever I look, there are no unattached pipes/hoses anywhere!
I've copied some pictures from the workshop manual, specifically the chapter named Engine Fuel Supply and its subchapters.
Let's start off with the basics:
Figure 38 of page 48
The above picture tells us that pipes/hoses numbered 2, 4, 6 and 8 are our primary concern here. The relevant caption to the picture reads:
2: Pop-off Valves with Y-coupling
4: Absolute Pressure Sensor Downstream of Throttle (with "hump")
6: Carbon Filter Washing Solenoid Valve
8: Anti-Evaporation System Thermal Valve
Now, these are my findings:
2 - this is the easy one, after re-installing the intake manifold there was only one unattached pipe/hose that were connected to an Y-coupling. It sits to the right of the engine if looking down upon it when standing in front of the car.
4 - this one ought also to be somewhat easy, as I never disconnected the pipe/hose from the Pressure Sensor - and that one is quite easy to find above and to the left of the engine. The pipe/hose that was connected to the Pressure Sensor, however, was not the one with the "hump" as shown in the picture, but another one. I therefore opted to connect the pipe/hose with the "hump" to this "nipple" and instead attached the pipe/hose from the Pressure Sensor to "nipple" 8 instead. The other end of the hose/pipe with the hump is attached to the Thermal Valve, sitting on top of the engine at the far back and beneath the inlet manifold. On my car it's colored in some shade of green.
6 - This is the "nipple" without any hose/pipe currently attached, as I cannot find one.
8 - Following the above mentioned picture as opposed to the picture's caption, I connected the hose/pipe without the "hump" from the Pressure Sensor to this one.
Figure 58 - Page 65
This picture is not in complete harmony with the previous one, its caption reads:
3 - Activated Carbon Filter Canister
4 - Pneumatic Washing Valve (I assume this is the "Carbon Filter Washing Solenoid Valve" mentioned for point 6 above)
5 - Inlet Manifold
6 - Thermal Valve (I assume this is the "Anti-Evaporation System Thermal Valve" mentioned for point 8 above)
This picture does show a "hump" in the hose/pipe that I opted to connect to "nipple" 4 from the previous picture, and whose other end is indeed attached to the Thermal Valve. Seems I made the right choice then...
Now it get's really interesting though.
Figure 64 - page 70
The relevant caption to this image reads accordingly:
5 - Activated Carbon Filter Canister
6 - Solenoid Valve (this is present in previous pictures as well though not captioned by me, this is thus
not the same as the Thermal Valve.
7 - Pneumatic Washing Valve (not shown attached to the Carbon Canister anymore, instead to the intake pipe between filter and turbocharger.
8 - Intake Manifold
It's all a little bit confusing to say the least, but I'm fairly sure that it's the pipe/hose for the Washing Valve that I'm lacking, but having spent a total of 2.5 hours looking for it without any progress I'm close to losing heart.
The workshop manual states that "
Any overpressure created in the tank (due to malfunctioning of the washing valve or clogged pipes) is discharged outside through the safety valve in the cap which has been suitably set for this purpose." I interpret this in a way that I could, at least for the time being - and in order to reach my MOT time in a few hours - just plug the "nipple" on the intake manifold and drive the car nonetheless?