hissing sound when spark plug pulled. Leaking injector?

[BMWSauberF1]

So I keep getting a misfire on cylinder 3 I’ve changed the coil pack and spark plug several times but it keeps fouling the plug. Today I had to pull over because the misfire got so bad I could barely drive the car. And when I pulled the cylinder 3 spark plug I could hear a hissing sound so I looked into the spark plug hole and it looks like I could see a little bit of movement in there like there was a little bit of liquid spraying. That, the hissing sound as well as the fact that changing the plug and coil hasn’t permanently fixed the issue only helped for a little while led me to believe that it’s got to be a leaky injector I take it right? When I heard that hiss I made sure to throw the new plug I had in there asap and put it all back together and drove it home but it was misfiring bad the whole way home unless I was on throttle pretty hard that’s the only time it would somewhat clear up. Does anyone know where I can download Ista since It looks like I’m gonna need it to be able to reprogram the new injectors when I replace them in the next couple days. Thanks for the help

[fstm5]

If it’s not the plugs or the coils, injectors would be the next issue. How many miles are you at? What year etc.