I found the gas leak part 2

[cyberstang5.0]

Yes, that means it's a bad O-ring. You can pick up a new set at the local autoparts store. Depending on which side it is, you might have to unbolt the upper manifold (if it's on the driver side). It's pretty easy to take them off, just pull
When you put the new O-rings on, oil them down with a little bit of 3-in-1 oil or light weight motor oil. This will help seal it better and let the injector slide into the fuel rail easier. I've done this to both set of injectos I've replaced and haven't had a problem (I went from 19lb-->24lb-->30lb ).