I was debating waiting till the cars in the garage in a few weeks having manifold swapped and decat put on, but managed to put a flat head into the side of the grommet and it lifted enough I could get a grip with the pliers, wasnt worried about damaging the grommet knowing it was being replaced,

But its all tight and fitting snug now, so hopefully wont need to be touched for a while now,

Going to wait for the decat to be fitted then if I still have running issues get it smoke tested for any other leaks