Have been getting the Code P04F0 so I was looking around the engine and came across this brightly coloured tube sticking out its solid inside not hollow so it’s not a wire casing anyone any ideas? 

 

It’s a 2021 Skoda Octavia 1ltr TSI . Thanks 

What's on the other end?! It looks like a foreign object, has anyone worked on the car recently?

If you mean the lime green thing isn't it some sort of plastic/'rubber' seal or marker to denote which part it's on if there's a choice (another option with a different colour ring on it), have you felt it with your fingers to see if it feels like a soft pliable O-ring sort of feel?

 

On a quick Google search P04F0 for VW comes up as EVAP system sensor circuit so if that's a sensor it might be something to do with that or someone messing with it.  To be sure codes are correct you do need an appropriate scan tool VW and to your model and year of vehicle and have that program on the scan tool fully up to date.

 

HTH.

 

Possibly the o ring for the intake pipe

Looks like the seal to me as well, has somebody been working on it?