HELP ! Fuel injector seats

[ben4866]

I thought my injector o-rings were leaking on my 1.8t AGU but on inspection it turned out to be the plastic seats which thread into inlet manifold.
Does anybody know how tight these fittings should be ? and whether they should have some sort of seal cos at the moment they seem to have something which resembles plumbers PTFE tape wrapped around the threads to seal them ?
Any help appreciated.
Thanks.

 

[RichA3Turbo]

They should be fairly tight, and there should be some form of PTFE/sealent or something that seals them up. Cylinder 3 tends to be the one to leak.