Could be start of head gasket what happens is with it sitting the oil or water sits on top of piston will run like crap until it clears it might not be though check not using water and oil
Have you tried new plugs could be that also check the wiring / plug onto each coil I had the same issue ended up being connections on cylinder 2 for me
Hi I was wondering how easy or difficult it would be to replace my 2.0 petrol to a 1.8t engine swap what I will need etc IE wiring loom fuel pump are engine mounts the same etc it's a 2002 b6