2008 s60 P0305 code after timing belt change

[jimmy57]

It is normal for the tensioner indicator to move that much.
A single cylinder misfire has a low chance of being timing off. That would affect all cylinders.
Pinched wire to that is a possibility but since you swapped coils it would be unlikely to do that twice.
It might be best to swap spark plugs between cylinders to see if the miss follows the #5 plug or stays at #5.

[Sardine]

...adjuster seemed to be moving/adjusting...

I can't tell you if the tensioner indicator moves while the car is being started. However, I have never observed any tensioner indicator movement in my car while the engine is idling. If your engine is misfiring at the time, then I don't know if the tensioner indicator should move or not.
I'm struggling to think of a reason for your misfire since the timing belt/tensioner seems ok. You've swapped both the coils and the plugs. The injector swap is a good idea. Air leak when the engine gets hot is another. The only problem is - what has it got to do with a timing belt change.

[oragex]

...adjuster seemed to be moving/adjusting...

I can't tell you if the tensioner indicator moves while the car is being started. However, I have never observed any tensioner indicator movement in my car while the engine is idling. If your engine is misfiring at the time, then I don't know if the tensioner indicator should move or not.
I'm struggling to think of a reason for your misfire since the timing belt/tensioner seems ok. You've swapped both the coils and the plugs. The injector swap is a good idea. Air leak when the engine gets hot is another. The only problem is - what has it got to do with a timing belt change.

Could it be if the tensioner was not properly adjusted the belt went loose and a valve hit the piston? But it wouldn't explain why the car runs fine after sitting for 10 min.
Perhaps recheck all the wires and connectors, at the injectors, temp sensor, etc. Maybe somewhere it got pulled while working around the belt.

[jerseykat1]

swap injectors and plugs. its not your timing. timing will effect all cylinders. failing injectors will usually only act up after some time on. its an easy check.